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Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

P1400: OECD 422 (Rat):

Systemic toxicity No Observed Adverse Effect Level (NOAEL) in males and females from F0 and F1 was considered to be 600mg/kg/day. At this dose level, histological findings (minimal to slight microscopic changes in the thyroid glands)observed were considered non-adverse in the absence of consistent changes in hormone levels. At 600 mg/kg/day, thyroid hormone changes were observed. However, given that the mechanism leading to these changes is unknown, and in the absence of effects on reproductive performance, their relevance to humans is uncertain and could be considered non-adverse.

Reproductive / developmental toxicity (NOAEL) was considered to be 600 mg/kg/day.

Link to relevant study records

Referenceopen allclose all

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2016-06-15 to 2018-02-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Version / remarks:
With an extension (3 m/f pups per litter to PND 70) to evaluate sexual maturation of F1 generation included.
Deviations:
yes
Remarks:
The deviations were considered to have not affected the integrity or validity of the study.
Qualifier:
according to guideline
Guideline:
other:
Version / remarks:
Commission Regulation (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
Deviations:
yes
Remarks:
These deviations were considered to have not affected the integrity or validity of the study.
Qualifier:
according to guideline
Guideline:
other:
Version / remarks:
United States Environmental Protection Agency (EPA). Health Effects Test Guidelines, OPPTS 870.3650, Combined Repeated Dose Toxicity with the Reproduction/Developmental Toxicity Screening Test, Office of Prevention, Pesticides and Toxic Substances EPA 712–C–00–368, (7101), July 2000.
Deviations:
yes
Remarks:
These deviations were considered to have not affected the integrity or validity of the study.
Principles of method if other than guideline:
The study was a modified OECD 422 study with extended F1 phase in which pups were followed from birth to sexual maturation (PND 70) in F1 pups.
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Justification for study design:
SPECIES: Rat, recognised by international guidelines as a recommended test system.

METHOD OF TEST ITEM ADMINISTRATION: Oral ingestion is a possible route of human exposure to the test item.

DOSE LEVELS: The dose levels were selected based on a dose-range-finding toxicity study in rats (Envigo Study S56026 1,2-Cyclohexanedicarboxylic Acid, 1butyl 2 (phenylmethyl) ester, CAS no.1200806-67-2: 14-day Repeated Dose Oral (Gavage) Range Finding Toxicity Study in the Rat).

HIGH DOSE: The high dose 600 mg/kg was based on mild signs of toxicity observed in animals at 1000 and 700 mg/kg in a 14-day dose-rangefinding study (Envigo DRF S56026), the clinical findings suggested that more prolonged dosing in the definitive study, together with the potentially greater sensitivity of the pregnant females, may exceed e maximum tolerated dose level and may result in significant effects on the ability of females to maintain offspring postpartum.

MID DOSE: The intermediate dose 300 mg/kg was intended to ensure that the interval between dose levels was within the limits prescribed in the OECD test guideline number 422 and might result in safe dose for exposure to the test item.

LOW DOSE: The low dose 150 mg/kg was intended to ensure that the interval between dose levels was within the limits prescribed in the OECD test guideline number 422 and was also above the cut-off for GHS classification as “toxic” according to the criteria for a 28-day repeat dose toxicity study.






Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: supplied by Envigo (Shardlow, UK) on behalf of the Sponsor (Polyadd Limited, U.K.); Batch no. 0900
- Expiration date of the lot/batch: 2017-01-17
- Purity test date: 2015-10-22

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: No special storage conditions are needed. Store away from incompatible materials (strong oxidizing agents). Keep the material sealed to avoid contact with moisture. Avoid high temperature.
- Stability under storage conditions: not specified
- Stability under test conditions: stable when stored at room temperature for 24 hours and stored refrigerated for 7 days.
- Solubility and stability of the test substance in the solvent/dispersant/vehicle/test medium: The homogeneity and stability was confirmed for the test item in vehicle formulations at nominal concentrations of 3.75 and 250 mg/mL when stored at room temperature for 24 hours and stored refrigerated for 7 days.

FORM AS APPLIED IN THE TEST (if different from that of starting material) : Liquid colorless
Species:
rat
Strain:
Wistar
Remarks:
Hannover Wistar rats
Details on species / strain selection:
Species: Rat - Species recognized by international guidelines as a recommended test system.
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Supplier (Charles River Laboratories, France); Breeder (Charles River Laboratories, Germany)
- Females (if applicable) nulliparous and non-pregnant: yes, females were nulliparous and nonpregnant
- Age at study initiation: 10-11 weeks (males and females)
- Weight at study initiation: Males: 350-394 g; Females: 215-257 g
- Fasting period before study: Not specified
- Housing: Cages with standard, granulated, S8-15 sawdust bedding (J. Rettenmaier & Söhne)
Premating period: 5 animals/cage - Makrolon cages-IV
Mating period: one male and one female/cage - Makrolon cages-I
Postmating: individually - Makrolon cages-I
- Diet (e.g. ad libitum): Pelleted standard Teklad 2014C rat/mouse maintenance diet ad libitum (supplied by Envigo RMS, S.L., batches no.: 010616MA, 012016MA and 022216MA, expiry dates: 02 October 2016, 16 October 2016 and 18 November 2016,respectively). Pelleted standard Teklad 2018C rat/mouse maintenance diet ad libitum(supplied by Envigo RMS, S.L., batch no.: 020916MA, expiry date: 5 November 2016), for lactating females and pups (until day 21 post partum).
- Water (e.g. ad libitum): Tap water in bottles ad libitum
- Acclimation period: 12 days prior to estrus cycle evaluation under test conditions

DETAILS OF FOOD AND WATER QUALITY: The diet was analyzed by the manufacturer for contaminants and to check its composition and the water underwent bacteriological, chemical and contaminant analysis. The results were included in the Annex 4 of the study report.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-23°C - monitored continuously
- Humidity (%): 40-70%
- Air changes (per hr): 15-20 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light (artificial fluorescent light)

ENVIRONMENTAL ENRICHMENT
- different types of material specific to the species (e.g. paper wool and sizzlenest) were provided to reduce stress, enhance well-being and improve behaviour.

IN-LIFE DATES: From: 2016-06-15 To: 2017-10-26
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
Oral route selected since oral ingestion is a possible route of human exposure to the test material. Test material was administered orally via gastric gavage using glass syringes.

PREPARATION OF DOSING SOLUTIONS: The appropriate amount of test material was added in a suitable glass container followed by the vehicle to reach the final concentration. The vial was gently inverted for a minimum five times to mix the formulation completely. This solution was aliquoted for each administration day in glass containers.

VEHICLE
- Justification for use and choice of vehicle (if other than water): corn oil (justification not specified)

- Concentration in vehicle: The amount of test material to be administered was calculated according to the most recently recorded body weight.
- Amount of vehicle (if gavage): 4 mL/Kg body weight
- Lot/batch no. (if required): Sigma-Aldrich Reference MKBV2080V and MKBW9504V
Details on mating procedure:
- M/F ratio per cage: 1:1
> Premating period (5 animals/cage) Makrolon cages -IV
> Mating period (one male and one female/cage) Makrolon cages -
> I Postmating (individually) Makrolon cages -I

- Length of cohabitation:
> During the mating period the females were housed with males within each dose group (one male:one female) until evidence of copulation was observed for a period of 18 or 24 hours.
> The females were removed and housed individually when:
a) The daily vaginal smear was sperm-positive, and/or
b) A copulation plug was observed. The day of mating evidence was designated day 0 post coitum.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
For each analysis occasion, freshly prepared test formulations were analyzed in accordance with the analytical procedure. Samples were disposed of once satisfactory results were achieved. The formulations received were diluted with tetrahydrofuran. An aliquot of test item formulation was accurately weighed into a volumetric flask and brought to volume with tetrahydrofuran and then shaken to dissolve. Where necessary, sample solutions were further diluted with tetrahydrofuran to achieve the working concentration.

The dose formulation concentration was determined twice during the study and once (top/middle/bottom) for homogeneity in samples taken from the formulation to be administered to Groups 2 to 4. One additional sample was also taken from the vehicle prepared. The formulations were quantified by gas chromatography according to the analytical procedure validated in Study YR67PH (DRF). The homogeneity and concentration of the formulations was analysed prior to the first day of dosing with the 1st analysis and concentration with the 2nd analysis. On both occasions, duplicate samples of the dosing solution (approx. 5 mL each) were transferred to labelled vials. Aliquot 1 was used for analysis and was shipped refrigerated in the dark to the PI (Paul Watson, Envigo Shardlow, UK). This aliquot was discarded after analysis. Aliquot-2 samples will be retained for any possible subsequent needs at Envigo CRS, S.A.U. and will be discarded after issuing the final phase or the final report unless otherwise requested by the Sponsor. Each sample was labelled at least with study number, phase number (YR67HP), aliquot number, treatment, concentration, formulation preparation date, formulation administration date and storage conditions. The test item was used as analytical
standard.
Duration of treatment / exposure:
Parental generation: starting two weeks before mating through a minimum of 28 days for males (after confirming female pregnancy) and until day 20 postpartum for females including the day before sacrifice.

Pups for sexual maturation from day 21 postpartum until sexual maturation 70 days postpartum (although direct treatment starts at or soon after weaning, all offspring have potential indirect exposure in utero and through the milk during lactation). Remaining pups (sacrificed on day 4 or 13 postpartum): not treated. Potential indirect exposure in
uteroand through the milk during lactation.
Frequency of treatment:
Once daily
Details on study schedule:
Parental generation: starting two weeks before mating through a minimum of 28 days for males (after confirming female pregnancy) and until day 20 postpartum for females including the day before sacrifice.

Pups for sexual maturation from day 21 postpartum until sexual maturation 70 days postpartum (although direct treatment starts at or soon after weaning, all offspring have potential indirect exposure in utero and through the milk during lactation).

Remaining pups (sacrificed on day 4 or 13 postpartum): not treated. Potential indirect exposure in utero and through the milk during lactation
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
Group 1
Dose / conc.:
150 mg/kg bw/day (nominal)
Remarks:
Group 2
Dose / conc.:
300 mg/kg bw/day (nominal)
Remarks:
Group 3
Dose / conc.:
600 mg/kg bw/day (nominal)
Remarks:
Group 4
No. of animals per sex per dose:
12/sex/group
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Dose levels were selected based on a dose-range-finding (DRF) toxicity study in rats (Envigo Study S56026: 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2 (phenylmethyl) ester, CAS no.1200806-67-2: 14-day Repeated Dose Oral (Gavage) Range Finding Toxicity Study in the Rat).

The low dose 150 mg/Kg was intended to ensure that the interval between dose levels was within the limits prescribed in the OECD test guideline number 422 and was also above the cut-off for GHS classification as “toxic” according to the criteria for a 28-day repeat dose toxicity study. The intermediate dose 300 mg/Kg was intended to ensure that the interval between dose levels was within the limits prescribed in the OECD test guideline number 422 and might result in safe dose for exposure to the test material. The high dose 600 mg/Kg was based on mild signs of toxicity observed in animals at 1000 and 700 mg/Kg in the 14-day DRF study (Envigo DRF S56026). The clinical findings
suggested that more prolonged dosing in the definitive study, together with the potentially greater sensitivity of the pregnant females, may exceed the maximum tolerated dose level and may result in significant effects on the ability of females to maintain offspring postpartum.

- Rationale for animal assignment (if not random): Animals were allocated at random based on mean body weight similarity among groups. Females were evaluated pre-exposure for estrus cyclicity.

- Fasting period before blood sampling for clinical biochemistry: Yes, animals were fasted overnight before blood sampling but allowed ad libitum access to water. The samples were collected early in the morning.
Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Mortality was checked for twice daily. Any rat sacrificed during the study was subjected to macroscopic examination.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Twice daily

BODY WEIGHT: Yes
- Time schedule for examinations:
P males: at pretest, on first day of dosing and twice weekly during the pre-pairing until sacrifice day (included).
P females: at pretest, on first day of dosing, twice weekly during the pre-pairing and pairing period and on days 0, 4, 7, 11, 14, 17 and 20 of pregnancy and within 24 hours of parturition (day 0 or 1 postpartum) and on days 4, 7, 14, 17 and 21 (as terminal body weight).

Pups for sexual maturation: twice weekly after weaning

Body weight during mating period is not reported.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
P males: at pretest, once weekly during the pre-pairing and weekly during pre-treatment, treatment and postpairing period.
P females: at pretest, once weekly during the pre-pairing and treatment periods and days 0-7, 7-14, 14-20 post coitum and days 1-7 and 7-14 postpartum.
Pups for sexual maturation: once weekly
Food consumption was not examined during the mating period.

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Not specified
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Not specified

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Males: following at least 28 administrations of the test item/vehicle (on day of sacrifice)
Females: on day 21 postpartum (on day of sacrifice)
- Anaesthetic used for blood collection: Yes (light isoflurane anesthesia)
- Animals fasted: Yes (The animals were fasted overnight before blood sampling but allowed ad libitum access to water. The samples were collected early in the morning)
- How many animals: five animals/sex/ group
- Parameters checked in table [No.2] were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Males: following at least 28 administrations of the test item/vehicle (on day of sacrifice)
Females: on day 21 postpartum (on day of sacrifice)
- Animals fasted: Yes (The animals were fasted overnight before blood sampling but allowed ad libitum access to water. The samples were collected early in the morning)
- How many animals: five animals/sex/ group
- Parameters checked in table [No.3] were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: before the first exposure to the test item, once weekly thereafter and one day before sacrifice. These observations were performed outside the home cage, in a standard arena, at least one hour after dosing (where applicable) to ensure identification of any transient effects
- Dose groups that were examined: performed on all test and control group animals
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

Grip strength assessment:
Grip strength (fore- and hind limbs) was measured in five randomly selected males per group once during the final week of treatment and at least one hour after dosing. Five randomly selected females per group were similarly evaluated on day 20 postpartum.

Motor activity assessment:
Motor activity was measured in the animals mentioned above with an activity motor system (AMS from Medical Instruments GmbH (FMI) and DeMeTec-Ams version 2.0 GmbH). Activity of the animals was recorded in 5-minute intervals over a 30-minute period and measured quantitatively (beam counts).

Sensory reactivity assessment:
Sensory reactivity to different stimuli was evaluated in the animals mentioned above. Details presented in Table No. 4.

IMMUNOLOGY: No

OTHER:
Thyroid Hormones: Blood samples were taken based on the following schedule:
• from all two pups per litter on day 4 after birth,
• from all pups per litter on day 13 after birth,
• from all surviving adult males, at termination,
• from all surviving dams on day 21 postpartum, and
• from cohort F1 on PND 70

All samples were stored under appropriate conditions after centrifugation (at 4 ºC and 2000 g for 10 minutes) to obtain serum. Samples from the PND 13 and 70 pups and adults were assessed for plasma levels of TSH and also serum for T4 in adult animals. Samples were shipped frozen to the PI (Envigo CRS Limited Test Site, Huntingdon) for analysis. Further assessment of T4 in serum samples from the adult animals at sacrifice and fromday-4 pups was done when relevant. Pup samples can be pooled by litter for thyroid hormone analyses. If not, an evaluation of potential effects on the thyroid function could be done in F1 offspring. This would comprise detailed microscopic examination of the thyroid glands from Day-13 offspring together with evaluation of potential effects upon plasma TSH levels in Day-4 and Day-13 offspring. Samples specifically intended for hormone determination were obtained at a comparable time of the day.

Analysis of serum samples for T4 was conducted at Envigo CRS Limited (Huntingdon) under the supervision of a Principal Investigator (Hariharasudhan Bose) for this study phase. Samples were analyzed using LC-MS/MS instrumentation, based on the bioanalytical method BM/2016/0632 (V
alidation study number: FF58YR).

Thyroid Hormones Acceptance Criteria
Since thyroid hormones are endogenous compounds, the acceptance criteria were widened. The accuracy (RE) determined at each QC concentration level was within ±20% (25% for LLOQ). The RE of at least 67% of the QC samples overall within the batch was within ±20% of their nominal concentration, including at least 50% at each concentration level. At least 75% of the calibration standards were within ±20% of the nominal concentration (±25% at LLOQ). When diluted test samples wereincluded in the batch, then 50% of the diluted QC samples in the batch (normally n = 2) were within 20% of their respective nominal concentration for the diluted sample data to be accepted.
Oestrous cyclicity (parental animals):
SPECIALIST EVALUATION P GENERATION
- Stage of oestrus:
Stage of estrus Vaginal smears for all females were collected for evaluation of oestrus cycle two weeks before treatment start to select female s with regular cycle. For the study Smearing of individual females was monitored daily from start of treatment until evidence of mating. Vaginal s mears were examined on the day of necropsy to determine the stage of the estrous cycle and allow correlation with histopathology of female re productive organs.

- Mating:
On day 15 of treatment, the mating period started while the test item was still being administered. During the mating period the females were ho used with males within each dose group (one male:one female) until evidence of copulation was observed for a period of 18 or 24 hours.
The females were removed and housed individually when:
a) The daily vaginal smear was sperm-positive, and/or
b) A copulation plug was observed. The day of mating evidence was designated day 0 post coitum.

- Parturition
From day 20 post coitum to 24 post coitum, the females were examined three times daily for signs of parturition. The duration of gestation (days) was recorded. The day of birth (completion of parturition) is defined as day 0 postpartum.

- Nursing:
The females that gave birth were checked twice daily, together with the litter status check, to observe whether they nursed their offspring.
Sperm parameters (parental animals):
A qualitative staging of spermatogenesis and histopathology evaluation of interstitial cells of all males from the control and high-dose groups was performed by the histopathologist.
Litter observations:
- Check at delivery:
>The number of stillbirths and of live and dead pups and any macroscopic anomalies were recorded for each litter within 24 hours of parturition (day 0 or 1 postpartum).
>If parturition ended before 7 am, this day was considered as day 1 postpartum and if parturition ended after 7 am this day was considered as day 0 postpartum.
>Pups were sexed, counted, weighed, identified with a pen and externally examined.

- Litter status Twice daily.
>Any pup sacrificed or found dead during the study was subjected to macroscopic examination.

- Litter clinical signs
> Pups were observed once daily.

- Litter sex:
> Days 1, 4, 13 and 21 postpartum

- Litter body weight:
> Days 1, 4, 7 and 13.
> Pups used for sexual maturation (3/sex/litter) were weighed on day 21 postpartum (PND) and then weekly until day 70 (included).

- Litter behavior test Day 1 postpartum:
>surface righting reflex

- Litter size standardization:
> On day 4 after birth, the size of each litter was adjusted by eliminating extra pups, as nearly as possible, to four pups per sex per litter. Pups were identified by finger tattoo.
>Ano-genital distance (AGD)
> The AGD of each pup was measured on PND 4 before size standardization. The distance between the genital papilla and anus was measured using a non-rigid caliper. Pup body weight was collected on the day the AGD was measured and the AGD was normalized to a measure of pup size, preferably the cube root of body weight.

Nipples/areolae:
>The number of nipples/areolae in male pups was counted on PND 13

Sexual maturation
>On day 13 after birth, three males and three females were selected at random and the size of each litter was adjusted by eliminating extra pups, when possible.
>Males: Examined daily from Day 38 of age for the completion of balano-preputial separation. Body weight was recorded on day of completion of separation.
>Females: Examined daily from Day 25 of age until vaginal opening occurred. Body weight was recorded on day of vaginal opening.
Postmortem examinations (parental animals):
SACRIFICE
Animals sacrificed in extremis were necropsied. Their organs were extracted and fixed but not weighed.

PARENTAL FEMALES
Females on day 21 postpartum and those showing total litter loss were deeply anesthetized with sodium pentobarbital administered intraperitoneally, exsanguinated by excision of the axillary vessels and aorta, and necropsied. The mated females that did not give birth or show signs of pregnancy were sacrificed 24-26 days post coitum as they were not mated again.

The postmortem examination of the external surface of the body, all orifices, cranial, thoracic and abdominal cavities and their contents with emphasis on the uterus, number of implantation sites was performed. The observation of the organs in situ and description of all macroscopic abnormalities are recorded.
A vaginal smear was examined to determine the stage of estrus cycle.

When no implantation site was evident, the uterus was placed in an aqueous solution of ammonium sulfide (Salewski, 1964) to accentuate possible hemorrhagic areas of implantation sites

PARENTAL MALES
After at least 29 administrations, all males were deeply anesthetized with sodium pentobarbital administered intraperitoneally, then exsanguinated by excision of the axillary vessels and aorta and necropsied subjected to confirmation of successful mating. The postmortem examination of the external surface of the body, all orifices, cranial, thoracic and abdominal cavities and their contents was performed. The observation of the organs in situ and description of all macroscopic abnormalities was recorded.

PATHOLOGY
The organs to be weighed (Table No. 5) were recorded on the scheduled necropsy dates for all surviving parental animals and group mean and adjusted values were calculated. Samples of tissues and organs were collected from all animals at necropsy and fixed in neutral phosphate buffered 4% formaldehyde solution (10% formalin) unless otherwise indicated as well as specimens of abnormal tissue.

Reproductive organs of all control and high dose animals as well as of animals selected for sexual maturation were also examined

All organ and tissue samples (except for the nose) of selected animals from groups 1 and 4 (5 animals/sex, as indicated in the actual pathology report) to be examined were processed, embedded, cut at an approximate thickness of 2-4 micrometers and stained with hematoxylin and eosin. Special stains were used at the discretion of the study pathologist. The bone marrow smears were stained using the May Grünwald-Giemsa method and kept at the test facility for possible further investigation.

HISTOLOGY
Slides of organs and tissues collected at necropsies of all animals to be evaluated, except for the bone marrow smear for which no test was planned, were examined by the pathologist at Envigo CRS, S.A.U. A description of all abnormalities is included in the report. Where possible, the microscopic findings were correlated with the gross observations. As test-item-related morphological changes were detected in thyroids in high-dose animals. The thyroid glands were examined in all adult animals from Group 2 and 3, as well as on day 70 PND from cohort F1.

A histopathology evaluation of interstitial cells of all males from the control and high-dose groups was performed by the histopathologist
Postmortem examinations (offspring):
SACRIFICE
On days 4 and 13 postpartum, selected pups were sacrificed by intraperitoneal injection of sodium pentobarbital and subjected to macroscopic examination. On day 70 postpartum, pups selected for evaluation of sexual maturation postpartum were also sacrificed by intraperitoneal injection of sodium pentobarbital and subjected to macroscopic examination.

NECROPSY
Offspring that died during the study and female pup no. 525 sacrificed for welfare reasons were examined externally and necropsied, except those excessively cannibalized or autolytic. Necropsy and a macroscopic examination were carried out on all other animals. Samples of organs and tissues with macroscopic alterations were taken and preserved in neutral phosphate buffered 4% formaldehyde solution for possible microscopic examination. A vaginal smear was taken to determine the stage of oestrus cycle, if considered necessary.
Statistics:
Please see the section 'Any other information on materials and methods incl. tables' for information on statistics.
Reproductive indices:
Mating Performance and Fertility
- Pre-coital time: Calculated as the time elapsing between initial pairing and the observation of positive evidence of mating.
- Fertility Indices: The following indices were calculated for each group:

1) Percentage Mating (%) = (Number of females mated / Number of females paired) x 100
2) Conception rate (%) = (Number of females achieving pregnancy / Number of females mated) x 100
3) Fertility index (%) = (Number of females achieving pregnancy / Number of females paired) x 100

- Implantation Losses (%): Group mean percentile pre-implantation and post-implantation loss was calculated for each female/litter as follows:
1) Pre–implantation loss = ((Number of corpora lutea - number of implantation sites) / (Number of corpora lutea)) x 100
2) Post–implantation loss = ((Number of implantation sites - Total number of offspring born) / (Number of implantation sites)) x 100

Gestation and Parturition Data: The following parameters were calculated for individual data during the gestation and parturition period of the parental generation.
- Gestation Length: Calculated as the number of days of gestation including the day for observation of mating and the start of parturition.
- Gestation Index:
Gestation Index (%) = (Number of females with living pups / Number of females pregnant) x 100
Offspring viability indices:
Litter Responses: values were first calculated for each litter and the group mean was calculated using the individual litter values. Group mean values included all litters reared to termination (Day 4 of age).

1) Post–natal loss = (Number of offspring / Number of offspring alive on Day 4) x 100

2) Viability Index (%) = (Number of alive pups on Day 4 / Number of offspring alive on Day 1) x 100

3) Live birth index (%) = (Number of offspring alive on Day 1 / Number of offspring delivered) x 100
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
There were no clinical signs considered to indicate an immediate or delayed reaction to treatment.

Salivation was observed during postnatal periods in males at 300 and 600 mg/Kg/day as well as during the treatment period at 600 mg/Kg/day. In females, salivation was observed in the same treatment groups during treatment, mating, gestation and lactation periods, as well as occasionally in females receiving 150 mg/Kg/day during gestation and lactation.

Although this was considered a test-item related effect, it could be related to palatability and thus not considered to be an adverse effect, as the animals could taste the test substance when the probe (used for gavage) was removed after administration.
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, non-treatment-related
Description (incidence):
There were no test material-related deaths.

Male no. 66 administered the test item at 600 mg/Kg/day was sacrificed on day 14 of treatment for animal welfare reasons, as there was a problem during the administration handling the previous day (the handler accidently lost hold of the animal as it tried to escape and it fell to the floor, after which it did not recover).

Females no. 109 (0 mg/Kg/day) and 161 (600 mg/Kg/day) were sacrificed for animal welfare reasons due to difficulties during parturition. As females were sacrificed, the corresponding litters were also killed and examined macroscopically:

- In the case of female no. 109, the cause for the poor condition was hematoma/hemorrhage, which most likely explains the sudden pallor displayed by that animal. Hysterectomy was performed and the foetuses (one male and one female in left uterine horn) that were found deadwere examined macroscopically, showingadvanced autolysis in abdominal and thoracic cavities.

- In female no. 161, 4 males and 4 females were alive when the hysterectomy was performed and 5 males and 2 females were found dead. No alterations were observed in their necropsy.

Females no. 102 (0 mg/Kg/day) and 149 (600 mg/Kg/day) were sacrificed on days 2 and 3 of lactation, respectively, due to total litter loss.

On day 24 of gestation, female no. 106 (0 mg/Kg/day) was sacrificed as no signs of parturition were observed. At necropsy, 1 implantation was observed in left uterine horn and consequently, this female was considered to be pregnant.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There was no effect on body weights during the study.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
There was no indication of an effect on food consumption during the treatment period.

The statistically significant increases noted at 300 and 600 mg/kg/day in males (postnatal days 8 and 15) or in females at 600 mg/kg/day on gestation day 14 were not considered to have been toxicologically relevant given theirmagnitude (no more than 1.2 times the Control mean values), as it was transient and as there were no effects in body weights that could be associated with it.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
There were no changes of toxicological relevance.

Males receiving 600 mg/kg/day showed significantly higher mean neutrophil and basophil values compared to the Control group. This tendency was also observed in females receiving 600 mg/kg/day but it was not statistically significant. There was no dose-effect relationship. Females on day 21 of lactation showed no other differences from the Control group.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Blood chemistry examination performed on the day of sacrifice in males revealed a dose-related incre ase in protein and globulin values in males. These differences were statistically significant at 300 and 600 mg/kg/day when compared to the Control group. However, this increase in protein and globulin values was not observed in females.

No other differences were observed when comparing the test item administered groups with the Control group.
Urinalysis findings:
not examined
Behaviour (functional findings):
effects observed, treatment-related
Description (incidence and severity):
Motor activity was considered not to be affected by the test item. Statistically significant increases observed in females at 600 mg/Kg/day (compared to Control) at 5 minutes were not considered relevant or test material-related, as they were occasional and there was no similar difference observed in males.

There was no indication of any adverse effects of the test item on sensory reactivity or grip strength assessments.

Given the magnitude (from 9 to 11 % versus Control) and the lack of a dose-effect relationship, the statistically significant differences observed at 300 and 600 mg/kg/day in the mean forelimb grip strength of femalesand at 600 mg/kg/day in the mean forelimb and hind limbs (11%) were not considered to be toxicologically relevant.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
There were no histopathological correlates for the increased liver weight in F0 males treated at the high dose.

In the kidneys of some F0 males treated with the high dose, increased amounts of hyaline droplets were seen. This correlates with the increased kidney weight in this group. However, the level of hyaline droplet accumulation observed was within the normal limits in this species and strain and was therefore not considered to be related to treatment.

In the testes, no cell or stage specific abnormalities were noted in males treated at 600 mg/kg/day. Interstitial cells were also assessed qualitatively, and no alterations were seen in treated males.

In the thyroid glands, minimal hypertrophy of the follicular epithelium was observed in some males of all treated groups, with a dose-effect relationship. It was also observed in isolated females of all treated groups.
Histopathological findings: neoplastic:
no effects observed
Other effects:
effects observed, non-treatment-related
Description (incidence and severity):
There was a minimal or slight hypertrophy of the follicular epithelium of the thyroid glands in males and females of all treated groups (150, 300 and 600 mg/kg/day). This finding could be considered to be within the normal variation in females at 150 and 300 mg/kg/day due to the low incidence recorded (2/12 at 150 mg/kg/day and 1/11 at 300 mg/kg/day), and the lack of effects in the T4 determinations. The decrease observed in T4 in F0 males at 600 mg/kg/day also correlates with the histopathological findings.
Reproductive function: oestrous cycle:
no effects observed
Description (incidence and severity):
No effect was observed in the length of the estrous cycle
Reproductive function: sperm measures:
no effects observed
Description (incidence and severity):
In the testes, no cell or stage specific abnormalities were noted in males treated at 600 mg/kg/day. Interstitial cells were also assessed qualitatively, and no alterations were seen in treated males.
Reproductive performance:
no effects observed
Description (incidence and severity):
No effect was observed on pre-coital interval, mating performance, fertility or gestation length or index when compared to the control group. No cell or stage specific abnormalities were noted in males treated at 600 mg/kg/day. Interstitial cells were also assessed qualitatively, and no alterations were seen in treated males either.
Mortality: There were no test-item-related deaths.

Clinical Signs: There were no clinical signs considered to indicate an immediate or delayed reaction to treatment.

Food Consumption: There was no indication of an effect on food consumption during the study.

Body Weight: There was no effect on body weights during the study.

FOB: Motor Activity: Motor activity was considered not to be affected by the test item.

FOB: Sensory Reactivity and Grip Strength: There was no indication of any adverse effects of the test item on sensory reactivity or grip strength assessments.

Hematology and Coagulation: There were no changes of toxicological relevance.

Clinical Biochemistry: Blood chemistry examination performed on the day of sacrifice in males revealed a dose-related increase in protein and globulin values in males. These differences were statistically significant at 300 and 600 mg/kg/day when compared to the Control group. However, this increase in protein and globulin values was not observed in females.

Macropathology: The macroscopic examination performed on day 21 postpartum in females and after at least 28 days of treatment in males revealed no test-item-related lesions. All findings were considered to be incidental and unrelated to treatment with the test item.

Organ Weights: A dose-related increase was recorded in kidney weights in all male treatment groups (maximum effect was observed in adjusted mean values at 600 mg/kg/day and was 17% higher versus Control). In addition, mean adjusted liver and spleen weights in males at 600 mg/kg/day were 40 and 22% higher, respectively, than those recorded in the Control group. In males, mean adjusted thymus weight was 18% lower at 600 mg/kg/day when compared to the Control group. All these differences were statistically significant.
Dose-related decreases in uterus, cervix and oviduct weights were observed (maximum effect 23% in adjusted mean values). Statistically significant differences were observed at 600 mg/kg/day.
Key result
Dose descriptor:
NOAEL
Effect level:
600 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: minimal to slight microscopic changes in the thyroid glands
Remarks on result:
other: At 600 mg/kg/day histological findings observed in males and females (minimal to slight microscopic changes in the thyroid glands) were considered non-adverse in the absence of consistent changes in hormone levels .
Key result
Critical effects observed:
no
Mortality:
not specified
Clinical signs:
no effects observed
Description (incidence and severity):
There were no clinical signs observed which were indicative of a reaction to the test item.

Female no. 525, administered the test item at 300 mg/kg/day, was sacrificed on day 18 of treatment phase. This female showed stereotypic movements (cycling) and prostration. Given the incidence and the lack of similar observations at 600 mg/kg/day, it cannot be considered a test-item-related effect.
Dermal irritation (if dermal study):
not examined
Mortality / viability:
no mortality observed
Description (incidence and severity):
There were no test-item-related deaths.

Female no. 525, administered the test item at 300 mg/kg/day, was sacrificed for welfare reasons, given the clinical signs observed
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There were no differences compared to the Control group.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There was no indication of an effect on food consumption during the treatment period.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
TSH ANALYSIS
Low mean values (statistically significant differences at 300 and 600 mg/kg/day) were recorded in offspring (pooled samples including males and females) on day 4 when compared to Control (53 and 60%, respectively). At 600 mg/kg/day, statistically significant high mean values were observed on PND 70 in males and females compared to Control (31 and 55%, respectively).

T4 ANALYSIS
In the T4 analysis, F0 males and PND 70 males administered the test item at 600 mg/kg/day showed mean serum T4 concentrations slightly lower than those of the Control group (16% and 8%, respectively). These differences were statistically significant. In addition, significant differences were also observed at 600 mg/kg/day in offspring on day 4 (low mean values, 19% with respect to Control).
Clinical biochemistry findings:
not specified
Urinalysis findings:
not examined
Sexual maturation:
no effects observed
Description (incidence and severity):
No adverse treatment-related effects were observed in the reproductive organs relating to alterations in the sexual maturation of male or female F1 pups.
Anogenital distance (AGD):
no effects observed
Description (incidence and severity):
There were no differences between the test-item-administered groups and Control animals.
Nipple retention in male pups:
no effects observed
Description (incidence and severity):
No test-item effect was observed in nipples areolae in male pups.
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
There were no differences in the mean weights of the thyroids or parathyroids in the test-item-administered animals compared to the Control group.
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
The thymus discoloration observed (Control Group: 1 male and 2 females, 150 mg/kg/day: 2 females and at 300 mg/kg/day: 1 female) was considered incidental and unrelated to treatment due to the distribution of this finding. No other macroscopic alterations were observed among the study animals.
Histopathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
All histological findings were considered to be incidental and unrelated to the test item.

A dose-related increase in incidence and/or severity of follicular cell hypertrophy in thyroid glands was seen in the test-item-administered males when compared with controls. Minimal hypertrophy of the follicular epithelium was observed in some females at 600 mg/kg/day, and was considered to represent normal variation in follicular epithelial height in juvenile rats, rather than a treatment effect.
Other effects:
no effects observed
Description (incidence and severity):
Check at Delivery / Litter Size and Sex:
- There was no effect of the test item on survival, litter size or sex ratio. There were no differences in the percentage of viable pups or pre/post-natal losses in the test item administered groups when compared with the Control group on days 4, 13 or 21.

Developmental Filial Data: Behavior, Nipples, Areolae and Sexual Maturation
- There were no differences in the surface righting test between the animals administered the test item and those of the Control group. In addition, no test-item effect was observed in balanopreputial separation or nipples areolae in males or in vaginal opening in females.
Behaviour (functional findings):
not examined
Developmental immunotoxicity:
not specified
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
600 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Reproductive and Developmental Toxicity
Key result
Critical effects observed:
no
Key result
Reproductive effects observed:
no

Table 6. F0 Food consumption - group mean values (g/animal/day): Males

Dose Group

 

Pre-treatment Period

Treatment Period

Postnatal Period

Day 8

Day 12

Day 8

Day 15

Day 8

Day 15

Statistical Test

 

Av

Av

Wi

Wi

Wi

Wi

Males

Control

Mean

26

26

21

20

18

19

SD

3.7

3.2

0.5

0.3

1.2

1.1

N

3

3

3

3

12

12

 

150 mg/Kg/day

Mean

25

25

21

20

18

18

SD

2.4

3.3

0.7

0.4

1.9

1.4

N

3

3

3

3

12

12

 

300 mg/Kg/day

Mean

25

25

22

22

20**

21*

SD

3.0

3.2

1.0

0.8

1.8

1.7

N

3

3

3

3

12

12

 

600 mg/Kg/day

Mean

38

39

22

22

22**

21**

SD

20.0

20.5

1.2

1.6

2.0

2.5

N

2

2

3

3

11

11

Av: Pre-treatment comparison of all groups using Analysis of variance followed by pairwise t-tests where appropriate

Wi: Treated groups compared with Control using Williams’ test

* p≤0.05

** p≤0.01

Table 7. F0 Food consumption - group mean values (g/animal/day): Females

Dose Group

 

Pre-treatment Period

Treatment Period

Gestation Period

Lactation Period

Day 8

Day 12

Day 8

Day 15

Day 7

Day 14

Day 20

Day 7

Day 14

Statistical Test

Av

Av

Wi

Wi

Wi

Wi

Wi

Sh

Sh

Females

Control

Mean

22

24

16

17

18

21

21

27

48

SD

4.3

5.5

0.8

0.5

2.0

2.0

2.4

6.7

10.9

N

3

3

3

3

12

12

12

9

9

 

150 mg/Kg/day

Mean

19

19

16

16

19

21

20

30

52

SD

3.0

2.9

0.2

0.1

2.3

1.6

2.3

4.7

4.2

N

3

3

3

3

12

12

12

12

12

 

300 mg/Kg/day

Mean

24

24

16

16

19

20

22

42

51

SD

5.2

5.5

0.2

0.3

2.3

2.2

2.8

31.3

4.9

N

3

3

3

3

12

12

12

12

11

 

600 mg/Kg/day

Mean

17

18

16

16

20

22*

23

27

45

SD

0.5

1.0

0.3

0.6

2.1

1.9

1.8

16.5

13.1

N

2

2

3

3

3

12

12

11

11

Av: Pre-treatment comparison of all groups using Analysis of variance followed by pairwise t-tests where appropriate

Sh: Treated groups compared with Control using Shirley’s test

Wi: Treated groups compared with Control using Williams’ test

* p≤0.05

** p≤0.01

Table 8. F0 Body weight - group mean values - Males

Period

Day

(Statistical Test)

Dose group:

Control

150 mg/Kg/day

300 mg/Kg/day

600 mg/Kg/day

Pre-treatment Period

Day 2 (Av)

Mean

344.6

343.6

344.3

346.7

SD

9.36

7.72

11.98

11.54

N

12

12

12

12

% of control

-

100

100

101

Day 12 (Av)

Mean

369.5

369.8

368.0

370.6

SD

10.59

11.03

12.42

10.85

N

12

12

12

12

% of control

-

100

100

100

 

Treatment Period

Day 1 (Wi)

Mean

371.7

372.8

371.9

373.8

SD

11.09

12.56

12.82

11.41

N

12

12

12

12

% of control

-

100

100

101

Day 4 (Wi)

Mean

374.2

378.3

375.7

377.3

SD

12.75

12.97

13.18

12.74

N

12

12

12

12

% of control

-

101

100

101

Day 8 (Wi)

Mean

382.2

384.6

381.7

385.3

SD

14.08

14.81

13.76

12.09

N

12

12

12

12

% of control

-

101

100

101

Day 11 (Wi)

Mean

384.7

383.4

385.0

381.9

SD

16.26

15.87

12.25

10.93

N

12

12

12

12

% of control

-

100

100

99

Day 14 (Wi)

Mean

390.0

391.0

390.4

391.9

SD

16.78

16.35

13.85

13.06

N

12

12

12

12

% of control

-

100

100

100

 

Postnatal Period

Day 1 (Wi)

Mean

387.1

386.2

386.2

387.5

SD

17.00

17.15

13.88

12.92

N

12

12

12

11

% of control

-

100

100

100

Day 3 (Wi)

Mean

389.4

389.8

391.2

392.9

SD

13.95

16.33

13.35

13.17

N

12

12

12

11

% of control

-

100

100

101

Day 7 (Wi)

Mean

391.8

391.7

394.3

396.1

SD

16.14

17.20

14.00

10.92

N

12

12

12

11

% of control

-

100

101

101

Day 10 (Wi)

Mean

395.6

394.0

397.9

399.6

SD

18.07

17.24

14.59

10.74

N

12

12

12

11

% of control

-

100

101

101

Day 14 (Wi)

Mean

398.4

396.5

399.8

399.5

SD

18.75

17.84

14.60

16.48

N

12

12

12

11

% of control

-

100

100

100

Day 17 (Wi)

Mean

398.8

404.3

402.7

396.0

SD

19.51

23.90

15.19

19.54

N

7

6

7

6

% of control

-

101

101

99

Day 21 (Wi)

Mean

395.8

405.6

400.6

400.1

SD

24.03

22.68

17.35

20.0

N

6

6

6

6

% of control

-

102

101

101

Day 24 (Wi)

Mean

398.8

407.3

402.0

400.1

SD

24.72

21.76

18.01

20.62

N

6

6

6

6

% of control

-

102

101

100

Day 28 (Tt)

Mean

396.7

-

399.8

-

SD

38.47

-

-

-

N

2

-

1

-

% of control

-

-

101

-

Table 9. F0 Body weight - group mean values - Females

Period

Day

(Statistical Test)

Dose group:

Control

150 mg/Kg/day

300 mg/Kg/day

600 mg/Kg/day

Pre-treatment Period

Day 2 (Av)

Mean

228.3

227.2

226.4

225.3

SD

10.21

8.61

9.79

10.01

N

12

12

12

12

% of control

-

100

99

99

Day 12 (Av)

Mean

232.2

232.4

231.5

230.7

SD

8.83

8.17

7.75

9.33

N

12

12

12

12

% of control

-

100

100

99

 

Treatment Period

Day 1 (Wi)

Mean

237.1

237.6

235.6

235.2

SD

12.22

9.52

9.69

10.95

N

12

12

12

12

% of control

-

100

99

99

Day 4 (Wi)

Mean

236.4

239.3

237.8

235.2

SD

11.89

7.04

13.00

11.85

N

12

12

12

12

% of control

-

101

101

99

Day 8 (Wi)

Mean

239.6

240.7

239.0

237.1

SD

11.28

8.12

12.85

12.44

N

12

12

12

12

% of control

-

100

100

99

Day 11 (Wi)

Mean

235.8

239.4

238.3

235.8

SD

10.65

7.98

12.20

12.51

N

12

12

12

12

% of control

-

101

101

100

Day 14 (Wi)

Mean

238.2

239.2

237.5

237.1

SD

11.52

7.23

10.32

12.16

N

12

12

12

12

% of control

-

100

100

100

 

Gestation Period

Day 0 (Wi)

Mean

240.7

243.4

241.3

239.2

SD

12.20

8.49

10.58

12.48

N

12

12

12

12

% of control

-

101

100

99

Day 4 (Wi)

Mean

255.3

255.5

255.5

253.1

SD

11.05

9.38

13.72

12.71

N

12

12

12

12

% of control

-

100

100

99

Day 7 (Wi)

Mean

263.0

264.3

263.3

261.6

SD

12.05

10.18

14.80

14.02

N

12

12

12

12

% of control

-

101

100

99

Day 11 (Wi)

Mean

277.4

278.4

275.6

275.4

SD

12.96

10.73

15.85

15.05

N

12

12

12

12

% of control

-

100

99

99

Day 14 (Wi)

Mean

286.8

288.9

287.9

289.5

SD

17.91

11.15

16.76

15.64

N

12

12

12

12

% of control

-

101

100

101

Day 17 (Wi)

Mean

305.6

312.8

310.3

313.5

SD

23.87

11.48

17.4

19.21

N

12

12

12

12

% of control

-

102

102

103

Day 20 (Wi)

Mean

328.0

339.9

339.7

338.2

SD

29.46

15.08

18.70

23.98

N

12

12

12

12

% of control

-

104

104

103

 

Lactation Period

Day 1 (Wi)

Mean

253.5

249.0

250.2

254.7

SD

15.27

15.58

15.94

17.73

N

10

12

12

11

% of control

-

98

99

100

Day 4 (Wi)

Mean

269.2

268.9

270.6

276.8

SD

10.74

14.68

14.62

16.43

N

9

12

11

11

% of control

-

100

101

103

Day 7 (Wi)

Mean

278.8

275.4

277.4

283.3

SD

8.11

15.07

12.72

18.41

N

9

12

11

11

% of control

-

99

100

102

Day 14 (Wi)

Mean

288.8

295.4

294.4

297.0

SD

12.62

18.49

18.41

22.64

N

9

12

11

11

% of control

-

102

102

103

Day 17 (Wi)

Mean

296.3

293.8

297.4

295.4

SD

15.36

14.64

16.52

22.23

N

9

12

11

11

% of control

-

99

100

100

Table 10. F0 FOB: Motor Activity - group meanabsolute values (beam counts)

Dose Group

Motor Activity

5 (min)

10 (min)

15 (min)

20 (min)

25 (min)

30 (min)

Total (min)

Males

Statistics Test

 

Wi

Wi

Wi

Wi

Wi

Wi

Wi

Control

Mean

179.4

138.4

86.2

126.0

82.8

46.8

659.6

SD

30.36

58.54

58.26

53.83

48.85

43.07

139.68

N

5

5

5

5

5

5

5

 

150 mg/Kg/day

Mean

201.8

76.2

41.0

109.4

69.4

22.2

520.0

SD

100.08

75.41

26.33

74.33

75.93

16.35

260.34

N

5

5

5

5

5

5

5

% of control

112

55

48

87

84

47

79

 

300 mg/Kg/day

Mean

199.4

141.2

124.8

95.4

64.6

101.2

726.6

SD

70.22

77.39

85.46

60.39

58.05

72.79

220.35

N

5

5

5

5

5

5

5

% of control

111

102

145

76

78

216

110

 

600 mg/Kg/day

Mean

276.4

199.4

134.8

136.6

88.2

18.8

854.2

SD

126.82

77.68

51.69

54.48

65.72

21.79

288.94

N

5

5

5

5

5

5

5

% of control

154

144

156

108

107

40

130

Females

Control

Mean

160.2

78.8

73.8

44.0

53.0

48.8

458.6

SD

19.32

50.26

57.80

46.82

47.75

80.42

205.16

N

5

5

5

5

5

5

5

 

150 mg/Kg/day

Mean

111.6

69.2

22.4

39.8

44.8

27.6

315.4

SD

80.62

55.93

32.35

38.00

39.47

40.83

195.63

N

5

5

5

5

5

5

5

% of control

70

88

30

90

85

57

69

 

300 mg/Kg/day

Mean

147.4

124.2

33.4

8.8

22.6

26.2

362.6

SD

26.23

97.49

58.06

8.61

29.11

43.38

154.14

N

5

5

5

5

5

5

5

% of control

92

158

45

20

43

54

79

 

600 mg/Kg/day

Mean

262.8**

152.2

116.2

55.4

24.0

25.0

635.6

SD

37.25

43.96

62.35

43.66

38.52

30.28

174.61

N

5

5

5

5

5

5

5

% of control

164

193

157

126

45

51

139

* p≤0.05

** p≤0.01

Table 11. F0 FOB: Grip Strength - group mean absolute values (g)

Dose Group

 

Forelimb Mean (g)

Hindlimb Mean (g)

Statistics Test

 

Wi

Wi

Males

Control

Mean

880.01

777.97

SD

104.052

175.758

N

5

5

 

150 mg/Kg/day

Mean

930.38

891.20

SD

104.071

230.406

N

5

5

% of control

106

115

 

300 mg/Kg/day

Mean

914.08

901.83

SD

127.802

104.196

N

5

5

% of control

104

116

 

600 mg/Kg/day

Mean

897.09

877.35

SD

72.559

165.634

N

5

5

% of control

102

113

Females

Control

Mean

860.65

765.07

SD

34.236

53.565

N

5

5

 

 150 mg/Kg/day

Mean

896.43

760.92

SD

34.236

25.793

N

5

5

% of control

104

99

 

 300 mg/Kg/day

Mean

957.66*

724.79

SD

58.709

82.191

N

5

5

% of control

111

95

 

 600 mg/Kg/day

Mean

940.01*

677.67*

SD

53.845

22.658

N

5

5

% of control

109

89

Wi: Treated groups compared with Control using Williams’ test

* p≤0.05

** p≤0.01

Table 12. F0 Hematology and Coagulation - Group mean value

Dose Group

 

Neutrophils (x 109/L)

Basophils (x 109/L)

LRT (x 1012/L)

Statistics Test

 

Wi

Wi

Wi

Males

Control

Mean

0.54

0.01

0.097

SD

0.148

0.004

0.0179

N

5

5

5

 

150 mg/Kg/day

Mean

0.49

0.01

0.088

SD

0.085

0.004

0.0160

N

5

5

5

 

300 mg/Kg/day

Mean

0.57

0.01

0.089

SD

0.149

0.004

0.0133

N

5

5

5

 

600 mg/Kg/day

Mean

0.88*

0.02**

0.090

SD

0.373

0.011

0.0111

N

5

5

5

Females

Control

Mean

0.089

0.01

0.0115

SD

0.313

0.007

0.0133

N

5

5

5

 

150 mg/Kg/day

Mean

0.82

0.01

0.106

SD

0.125

0.004

0.0172

N

5

5

5

% of control

91

120

92

 

300 mg/Kg/day

Mean

0.66

0.01

0.113

SD

0.078

0.000

0.0130

N

5

5

5

% of control

74

100

98

 

600 mg/Kg/day

Mean

1.27

0.02

0.093*

SD

0.433

0.009

0.0159

N

5

5

5

% of control

142

160

93

Wi: Treated groups compared with Control using Williams’ test

* p≤0.05

** p≤0.01

LRT: Reticulocyte maturity index

Table 13. F0 Clinical Biochemistry - Group mean values post mating

Dose Group

 

Protein (g/L)

Globulin (g/L)

Statistics Test

 

Wi

Wi

Males

Control

Mean

62.14

22.48

SD

1.80

1.70

N

5

5

 

150 mg/Kg/day

Mean

63.84

24.66

SD

2.02

2.06

N

5

5

 

300 mg/Kg/day

Mean

65.08*

25.12*

SD

2.64

2.59

N

5

5

 

600 mg/Kg/day

Mean

68.82**

26.96**

SD

2.13

1.09

N

5

5

Females

Control

Mean

53.64

17.62

SD

1.849

2.364

N

5

5

 

150 mg/Kg/day

Mean

53.62

17.38

SD

1.743

2.009

N

5

5

% of control

100

99

 

300 mg/Kg/day

Mean

55.66

17.72

SD

1.716

1.571

N

5

5

% of control

104

101

 

600 mg/Kg/day

Mean

55.20

19.02

SD

2.758

2.123

N

5

5

% of control

103

108

Wi: Treated groups compared with Control using Williams’ test

* p≤0.05

** p≤0.01

Table 14. F0 Organ weights - group mean absolute and adjusted values (g)

Dose Group

 

Organ

Kidneys

Liver

Spleen

Thymus

Uterus and Cervix and Oviducts

Statistics Test

 

Wi

Wi

Wi

Wi

Sh

Males

Control

Mean

2.237

10.908

0.602

0.370

-

SD

0.194

0.866

0.027

0.044

-

N

5

5

5

5

-

Adjusted Mean

2.252

11.137

0.621

0.378

-

 

150 mg/Kg/day

Mean

2.313

13.045

0.668

0.295

-

SD

0.231

2.330

0.138

0.067

-

N

5

5

5

5

-

% of control

103

120

111

80

-

Adjusted Mean

2.312

13.021

0.666

0.294

-

 

300 mg/Kg/day

Mean

2.431

12.628

0.626

0.278

-

SD

0.172

2.633

0.114

0.078

-

N

5

5

5

5

-

% of control

109

116

104

75

-

Adjusted Mean

2.416

12.387

0.605

0.270

-

 

600 mg/Kg/day

Mean

2.612

15.260

0.736

0.304

-

SD

0.205

1.395

0.083

0.068

-

N

5

5

5

5

-

% of control

117

140

122

82

-

Adjusted Mean

2.615*

15.296**

0.739*

0.306*

-

Females

Control

Mean

1.808

10.381

0.680

0.219

0.730

SD

0.131

0.802

0.089

0.039

0.229

N

5

5

5

5

9

Adjusted Mean

1.810

10.394

0.681

0.219

0.731

 

150 mg/Kg/day

Mean

1.783

10.650

0.699

0.239

0.664

SD

0.104

0.398

0.101

0.061

0.129

N

5

5

5

5

12

% of control

99

103

103

109

91

Adjusted Mean

1.795

10.723

0.702

0.239

0.667

 

300 mg/Kg/day

Mean

1.931

10.859

0.705

0.232

0.618

SD

0.074

0.496

0.095

0.040

0.117

N

5

5

5

5

11

% of control

107

105

104

106

85

Adjusted Mean

1.943

10.927

0.708

0.232

0.619

 

600 mg/Kg/day

Mean

1.801

11.624

0.673

0.213

0.563

SD

0.230

1.887

0.101

0.038

0.146

N

5

5

5

5

11

% of control

100

112

99

97

77

Adjusted Mean

1.776

11.471

0.666

0.214

0.559*

Wi: Treated groups compared with Control using Williams’ test

Sh: Treated groups compared with Control using Shirley’s test

* p≤0.05

** p≤0.01

- Not applicable

Table 15. Mean plasma TSH concentrations (pg/mL)

Dose Group

 

F0 Males

F0 Female on Day 21 Post-partum

Statistics Test

Wi

Sh

Control

Mean

1560

1860

SD

1010

N/A

N

12

9

 

150 mg/Kg/day

Mean

1800

543

SD

749

134

N

12

12

 

300 mg/Kg/day

Mean

1550

607

SD

685

20

N

10

11

 

600 mg/Kg/day

Mean

1350

751

SD

571

472

N

10

10

Wi: Treated groups compared with Control using Williams’ test

Sh: Treated groups compared with Control using Shirley’s test

* p≤0.05

** p≤0.01

 

Table 16. Mean serum T4 concentrations (pg/mL)

Dose Group

 

F0 Males

F0 Female on Day 21 Post-partum

Statistics Test

 

Wi

Sh

Control

Mean

47600

39578

SD

6512

5434

N

12

9

 

150 mg/Kg/day

Mean

49158

39333

SD

6331

6447

N

12

12

 

300 mg/Kg/day

Mean

44650

37209

SD

5207

3529

N

10

11

 

600 mg/Kg/day

Mean

40109**

39191

SD

3739

7049

N

11

11

Wi: Treated groups compared with Control using Williams’ test

Sh: Treated groups compared with Control using Shirley’s test

* p≤0.05

** p≤0.01

Table 17. Summary of Reproductive Performance

Treatment Group

Control

150 mg/Kg/day

300 mg/Kg/day

600 mg/Kg/day

Total Females

12

12

12

12

    Unscheduled Deaths Prior to Pairing

0

0

0

0

Females Paired

12

12

12

12

    Unscheduled Deaths Prior to Pairing

0

0

0

0

Females Mated

12

12

12

12

    Pregnant Females

12

12

12

12

       Euthanized for welfare reasons

1

0

0

1

       Total litter loss

1

0

1

0

       Failed to litter

1

0

0

0

   Non Pregnant Females

0

0

0

0

   Not Parturition

2

0

0

0

Number of Conception Day

 

 

 

 

    Day 1

3

0

2

1

    Day 2

4

3

2

2

    Day 3

5

6

6

6

  Day 4

0

3

2

3

Percentage Mating (%)

100

100

100

100

Conception rate (%)

100

100

100

100

Fertility Index (%)

100

100

100

100

Gestation Index (%)

75

100

100

100

Post-Implantation Loss (%)

12.2

7.8

6.2

9.1

Estrous cycle (mean length)

4.0

4.0

4.0

4.2

Females showing evidence of copulation

12

12

12

12

Females achieving pregnancy

12

12

12

12

Dams with live young

 

 

 

 

  Day 1

9

12

12

12

  Day 4

9

12

11

11

Implants / dam (mean)

11.7

13.8

12.3

13.3

Live pups / dam

 

 

 

 

  Day 1 (mean)

9.9

11.9

11.6

10.4

  Day 4 (mean)

9.6

11.8

11.2

10.0

Sex Ration (M:F)

 

 

 

 

  Day 1 (mean)

0.98

0.86

0.99

0.79

  Day 4 (mean)

0.95

0.88

0.98

0.77

Litter weight

 

 

 

 

  Day 1 (mean)

5.64

5.31

5.49

5.62

  Day 4 (mean)

8.15

7.85

8.08

9.00

  Day 13 (mean)

30.17

29.93

28.66

31.29

Pup weight: Males

 

 

 

 

  Day 1 (mean)

5.82

5.40

5.61

5.75

  Day 4 (mean)

8.36

7.92

8.21

9.14

  Day 13 (mean)

30.53

30.08

28.98

31.53

Pup weight: Females

 

 

 

 

  Day 1 (mean)

5.47

5.22

5.36

5.49

  Day 4 (mean)

7.94

7.78

7.95

8.85

  Day 13 (mean)

29.81

29.77

28.35

31.05

Pup AGD Males Day 4 (mean)

3.54

3.39

3.28

3.50

Pup AGD Females Day 4 (mean)

1.39

1.50

1.47

1.55

Loss of offspring

 

 

 

 

  Pre-natal / post-implantations (implantation minus live births)

 

 

 

 

   Females with 0

3

2

6

3

   Females with 1

0

3

3

2

   Females with 2

3

5

3

1

   Females with ≥3

3

2

0

6

 Post-natal (live births minus alive on Day 4)

 

 

 

 

   Females with 0

2

2

1

2

   Females with 1

2

0

0

0

   Females with 2

1

0

1

2

   Females with ≥3

4

10

10

8

Table 18. F1 Food consumption - group mean values (g/animal/day)

Dose Group

 

Days

1-8

Days

8-15

Days

15-22

Days

22-29

Days 29-36

Days 36-43

Days

43-50

Statistical Test

Wi

Wi

Wi

Wi

Wi

Wi

Wi

Males

 

Control

Mean

9

15

19

19

20

20

20

SD

0.8

3.5

1.8

1.4

2.0

1.6

1.1

N

9

9

9

9

9

9

9

 

150 mg/Kg/day

Mean

8

15

19

19

20

20

19

SD

0.8

4.4

1.6

1.1

1.4

1.5

1.4

N

12

12

12

12

12

12

12

% of Control

94

102

101

100

98

99

98

 

300 mg/Kg/day

Mean

8

15

20

20

21

21

20

SD

1.4

3.0

2.6

1.9

1.7

1.5

1.6

N

11

11

11

11

11

11

11

% of Control

96

103

104

103

103

103

101

 

600 mg/Kg/day

Mean

7*

15

20

21

21

21

20

SD

1.5

3.8

2.0

1.5

1.8

1.8

1.7

N

11

11

11

11

11

11

11

% of Control

86

102

103

106

103

104

102

Females

Control

Mean

8

13

15

14

15

14

13

SD

0.9

1.6

1.1

1.3

2.7

1.2

0.9

N

9

9

9

9

9

9

9

 

150 mg/Kg/day

Mean

8

13

15

14

14

15

14

SD

0.6

1.2

1.2

0.8

1.8

2.0

1.0

N

12

12

12

12

12

12

12

% of Control

98

101

100

103

97

106

104

 

300 mg/Kg/day

Mean

8

14

15

15

15

15

14

SD

1.1

1.8

1.4

2.2

3.2

1.5

1.3

N

11

11

11

11

11

11

11

% of Control

98

106

104

108

100

104

107

 

600 mg/Kg/day

Mean

7

13

16

15

14

15

14

SD

1.4

2.4

1.3

1.1

1.4

1.2

1.1

N

11

11

11

11

11

11

11

% of Control

92

103

107

108

97

104

106

Table 19. Litter Responses - F0/F1 Generations - group mean values

Dose Group

 

Live birth

index (%)

Viability

index Day 4 (%)

Viability

index Day 13 (%)

Viability

index Day 21 (%)

Postnatal loss Day 4 (%)

Postnatal loss Day 13 (%)

Postnatal loss Day 21 (%)

Statistics Test

Fe

Fe

 

 

 

 

 

Females

Control

Mean

84.5

91.9

100.0

100.0

8.1

0.0

0.0

SD

31.29

14.03

0.00

0.00

14.03

0.00

0.00

N

10

9

9

9

9

9

9

 

150 mg/Kg/day

Mean

94.3

98.8

100.0

100.0

1.2

0.0

0.0

SD

8.65

2.80

0.00

0.00

2.80

0.00

0.00

N

12

12

12

12

12

12

12

% of Control

112

107

100

100

15

100

100

 

300 mg/Kg/day

Mean

100.0*

89.9

100.0

100.0

10.1

0.0

0.0

SD

0.00

28.97

0.00

0.00

28.97

0.00

0.00

N

12

12

11

11

12

11

11

% of Control

118

98

100

100

125

100

100

 

600 mg/Kg/day

Mean

94.2

94.3

100.0

100.0

5.7

0.0

0.0

SD

14.48

13.83

0.00

0.00

13.83

0.00

0.00

N

12

11

11

11

11

11

11

% of Control

112

103

100

100

71

100

100

Fe: Treated groups compared with Control using Fisher’s exact test

* p≤0.05

Table 20. F1 Macropathology - group distribution of findings

Tissue/Organ and Findings

Number of animals affected

Males

Females

Control

150 mg/Kg/day

300 mg/Kg/day

600 mg/Kg/day

Control

150 mg/Kg/day

300 mg/Kg/day

600 mg/Kg/day

Number of Animals

24

36

32

30

25

36

34

30

Number of animals within normal limits

23

36

32

30

23

34

33

30

Thymus

Abnormal color

1

0

0

0

2

2

1

0

Table 21. F1 Organ weights - group mean absolute and adjusted values (g)

Dose Group

 

Terminal

Body weight (g)

Thyroids and

Parathyroids (g)

Males

Statistics Test

 

Wi

Sh

Control

Mean

292.2

0.017

SD

20.1

0.005

N

25

25

 

150 mg/Kg/day

Mean

286.5

0.014

SD

27.6

0.003

N

36

36

% of Control

98

84

 

300 mg/Kg/day

Mean

292.0

0.016

SD

26.1

0.004

N

32

32

% of Control

100

95

 

600 mg/Kg/day

Mean

288.8

0.015

SD

24.0

0.003

N

30

30

% of Control

99

90

Females

Statistics Test

 

Wi

 

Control

Mean

194.3

0.014

SD

13.8

0.004

N

25

25

 

150 mg/Kg/day

Mean

192.2

0.012

SD

13.7

0.003

N

36

36

% of Control

99

86

 

300 mg/Kg/day

Mean

195.0

0.014

SD

14.0

0.004

N

33

33

% of Control

100

100

 

600 mg/Kg/day

Mean

198.3

0.013

SD

17.4

0.004

N

30

30

% of Control

102

93


Conclusions:
Based on the results observed, the systemic toxicity No Observed Adverse Effect Level (NOAEL) in males and females rats was determined to be 600 mg/Kg/day. At this dose level, histological findings (minimal to slight microscopic changes in the thyroid glands) observed were considered non-adverse in the absence of consistent changes in hormone levels. At 600 mg/Kg/day, thyroid hormone changes were observed. However, given that the mechanism leading to these changes is unknown, and in the absence of effects on reproductive performance, their relevance to humans is uncertain and could be therefore, considered non-adverse.
 
Based on lack of adverse treatment-related effects observed, the NOAEL for reproductive / developmental toxicity was determined to be 600 mg/Kg/day.
Executive summary:

A key Guideline 422 study was conducted to evaluate the effects of repeated oral (gavage) administration of the test material (P1400: 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2 (phenylmethyl) ester, CAS 1200806-67-2) to rats during a four-week period in F0 males two weeks before mating through a minimum of 28 days (after confirming female pregnancy), until day 20 postpartum for females including the day before sacrifice, and from birth to sexual maturation (PND 70) in F1 pups. 12 rats per sex per dose received the test material in corn oil once daily via oral gavage at does of 150, 300, or 600 mg/Kg/day while the control animals received corn oil only.

 

Animals were observed twice daily for mortality and for any clinical signs following administration of the test material. Parameters such as body weight, food consumption, behavioural assessments such as grip strength, motor activity, and sensory reactivity assessment were evaluated for. Additionally, blood samples were extracted from the retro-orbital plexus of all animals under light isoflurane anesthesia and clinical biochemistry as well as haematology assessments were undertaken. Blood samples were taken from all surviving adult males, at termination and from all surviving dams on day 21 postpartum for thyroid hormone analysis. At necropsy, post-mortem examination of the external surface of the body, all orifices, cranial, thoracic and abdominal cavities and their contents with emphasis on the uterus (females only), number of implantation sites (females only) was performed. Organ weights were recorded and all organ and tissue samples (except for the nose) of selected animals from the control and high dose groups (5 animals/sex) were processed, embedded, cut at an approximate thickness of 2-4 micrometers and stained with hematoxylin and eosin. Reproductive organs of all control and high dose animals as well as of animals selected for sexual maturation were also examined. Histopathological analysis was undertaken and slides of organs and tissues collected at necropsies of all animals to be evaluated, except for the bone marrow smear for which no test was planned, were examined by the pathologist. Additionally, based on treatment-related morphological changes detected in thyroids in high-dose animals, this organ from the other treatment group animals were examined in all adult animals. A qualitative staging of spermatogenesis and histopathology evaluation of interstitial cells of all males from the control and high-dose groups was also performed.

 

No treatment-related mortality, clinical signs (other than salivation) or effects on functional observation battery were observed in the parental generation. There was no effect on body weights during the study and there was no indication of an effect on food consumption during the treatment period. The statistically significant increases noted at 300 and 600 mg/Kg/day in males (postnatal days 8 and 15) or in females at 600 mg/Kg/day on gestation day 14 were not considered to have been toxicologically relevant given their magnitude (no more than 1.2 times the Control mean values), as it was transient and as there were no effects in body weights that could be associated with it. Haematology, coagulation and clinical biochemistry effects observed, in the absence of a dose-effect relationship (neutrophil and basophils) or given that the differences were only observed in one sex (protein and globulin values in males), were not considered to be toxicologically relevant. Gross necropsy did not reveal any remarkable findings and all findings were considered to be incidental and unrelated to treatment with the test material. Reproductive parameters of pre-coital, fertility or gestation length or index were unaffected by treatment. There were no effects on survival, litter size, sex ratio and no adverse effect on offspring growth. No adverse effects were observed in the reproductive organs relating to alterations in the sexual maturation.

 

In parental males, a dose-related increase in mean kidney weights, correlating to an increase in the amount of hyaline droplets, was observed at histopathological examination. However, this was considered to be within the normal historical range for rats of this strain and age. At 600 mg/Kg/day in parental animals, there were no histopathological findings that correlate with the increased liver and spleen weights in males or in the decrease in uterus, cervix and oviducts in females. A minimal or slight hypertrophy of the follicular epithelium of the thyroid glands was observed in males and females of all treated groups (150, 300 and 600 mg/Kg/day). This finding could be considered to be within the normal variation in females at 150 and 300 mg/Kg/day due to the low incidence recorded (2/12 at 150 mg/Kg/day and 1/11 at 300 mg/Kg/day), and the lack of effects in the T4 determinations. The decrease observed in T4 in parental males at 600 mg/Kg/day also correlated with the histopathological findings.

 

For the F1 generation, no changes in body weights or food consumption, clinical or necropsy signs were observed which were indicative of a reaction to the test material. There were no changes in the mean weights of the thyroids or parathyroids. In males, there was a dose-related increase in the incidence and/or severity of follicular cell hypertrophy in thyroid glands. The decrease in T4 and increase observed in TSH the PND 70 males at 600 mg/Kg/day also correlated with the histopathological findings. In females, minimal hypertrophy of the follicular epithelium in the thyroid glands was observed in a few animals treated at 600 mg/Kg/day (3 affected females from 30 observed).

 

Based on the results observed, the systemic toxicity No Observed Adverse Effect Level (NOAEL) in males and females rats was determined to be 600 mg/Kg/day. At this dose level, histological findings (minimal to slight microscopic changes in the thyroid glands) observed were considered non-adverse in the absence of consistent changes in hormone levels. At 600 mg/Kg/day, thyroid hormone changes were observed. However, given that the mechanism leading to these changes is unknown, and in the absence of effects on reproductive performance, their relevance to humans is uncertain and could be therefore, considered non-adverse.

 

Based on lack of adverse treatment-related effects observed, the NOAEL for reproductive / developmental toxicity was determined to be 600 mg/Kg/day.

Endpoint:
extended one-generation reproductive toxicity - basic test design (Cohorts 1A, and 1B without extension)
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the extended one-generation reproductive toxicity study does not need to be conducted because there are no results from available repeated dose toxicity studies that indicate adverse effects on reproductive organs or tissues, or reveal other concerns in relation with reproductive toxicity
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
Testing not required based on tonnage band the substance subject to this registration is in Annex IX.
According to Section 8.7.3, column 1 and 2, the study does not need to be conducted if an OECD 422 screening studies is available and indicate that indicate no adverse effects on reproductive organs or tissues or reveal other concerns in relation with reproductive toxicity.
An OECD 422 screening study has been performed at Envigo Laboratories. Based on the results of this study, the No Observed Adverse Effect Level NOAEL for the systemic toxicity in males and females from F0 and F1 was considered to be 600 mg/kg/day. At this dose level, histological findings (minimal to slight microscopic changes in the thyroid glands) observed were considered non-adverse in the absence of consistent changes in hormone levels. At 600 mg/kg/day, thyroid hormone changes were observed. However, given that the mechanism leading to these changes is unknown, and in the absence of effects on reproductive performance, their relevance to humans is uncertain and could be considered non-adverse. The No Observed Adverse Effect Level (NOAEL) for reproductive / developmental toxicity was considered to be 600 mg/kg/day.
Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
600 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
Key study, study conducted according OECD TG 422 Guideline and under GLP conditions.
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available

Effects on developmental toxicity

Description of key information

P1400: OECD 414 (Rat):

Developmental toxicity: NOAEL (Rat) = 1000 mg/kg/day (OECD 414)

Link to relevant study records
Reference
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2020-SEP-17 to 2021-NOV-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Version / remarks:
June 2018
Deviations:
yes
Remarks:
None of the deviations was considered to have affected the outcome or integrity of the study.
Qualifier:
according to guideline
Guideline:
EU Method B.31 (Prenatal Developmental Toxicity Study)
Version / remarks:
May 2008
Deviations:
yes
Remarks:
None of the deviations was considered to have affected the outcome or integrity of the study.
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)
Version / remarks:
August 1998
Deviations:
yes
Remarks:
None of the deviations was considered to have affected the outcome or integrity of the study.
Qualifier:
according to guideline
Guideline:
other: Agricultural Production Bureau, Ministry of Agriculture, Forestry and Fisheries, Japan, 12 - Nousan No. 8147
Version / remarks:
November 2000
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material: Valtris Speciality Chemicals (Bridgeport, NJ, USA); Batch Number: 5840
- Purity, including information on contaminants, isomers, etc.: 99.609% (GC)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability and homogeneity of the test material in the vehicle/solvent under test conditions (e.g. in the exposure medium) and during storage: Homogeneous and stable for 24 hours at room temperature and for seven days when stored refrigerated (2°C to 8°C).

FORM AS APPLIED IN THE TEST (if different from that of starting material): Clear, oily liquid

OTHER SPECIFICS
- Expiration date: 2021-MAR-04
Species:
rat
Strain:
Wistar
Remarks:
Crl:WI(Han)
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK) Limited (Margate, Kent, CT9 4LT, England)
- Females (if applicable) nulliparous and non-pregnant: Not specified
- Age at study initiation: 9-10 weeks old
- Weight at study initiation: Females: 177 - 248 grams
- Fasting period before study: Not specified
- Housing: individually in solid-floor cages
- Diet (e.g. ad libitum): pelleted rodent diet, VRF1 (manufactured by SDS) supplied by Charles River (UK) Limited ad libitum
- Water (e.g. ad libitum): mains tap water (in bottles) ad libitum
- Acclimation period: at least 2 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C to 24°C
- Humidity (%): 40-70%
- Air changes (per hr): Room airconditioned (number of air changes not specified)
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light

IN-LIFE DATES: From: 2020-SEP-17 To: 2020-OCT-05
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test material was formulated within the stability period, for each group separately, as a suspension in corn oil by weighing directly into the final preparation container, with the required quantity of vehicle needed to make up to final weight and stirred until homogeneous. Formulations were divided into daily aliquots and stored refrigerated (2°C to 8°C) and stirred from at least 15 minutes before the start of dosing until the completion of their use for dosing, to ensure thorough re-suspension and homogeneity.

VEHICLE
- Justification for use and choice of vehicle (if other than water): Corn oil (justification not specified)
- Concentration in vehicle: 0, 25, 75, or 250 mg/mL for the control, 100, 300, and 1000 mg/kg/day dose groups, respectively.
- Amount of vehicle (if gavage): 4 mL/kg
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Concentration Analyses:
Sets of samples (for analysis or for contingency) were taken from each test material formulation prepared for use on the first day of dosing and on one day towards the end of the dosing period. Samples were analysed under Covance Reference Number 8451750 using the method validated in Covance Study Number: LB14VL (2020).

Homogeneity and Stability:
Homogeneity and stability of test material formulations prepared at concentrations of 3.75 and 250 mg/mL, spanning those used in this study (25 to 250 mg/mL), were examined in an earlier formulation validation study (Envigo Study Number: S56026 (2018)).
Details on mating procedure:
- Impregnation procedure: purchased timed pregnant
Duration of treatment / exposure:
Day 6 to Day 19 of gestation, inclusive
Frequency of treatment:
Once daily
Duration of test:
Day 6 to Day 19 of gestation, inclusive
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
Group 1 (Control - corn oill)
Dose / conc.:
100 mg/kg bw/day (nominal)
Remarks:
Group 2 (Low dose)
Dose / conc.:
300 mg/kg bw/day (nominal)
Remarks:
Group 3 (Intermediate dose)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
Group 4 (High dose)
No. of animals per sex per dose:
22/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale:
Dose levels were selected in consultation with the Sponsor after examining existing toxicity data (14-day Repeated Dose Oral (Gavage) Range Finding Toxicity Study in the Rat. Envigo Study Number: S56026; a 28 Day Oral (Gavage) Toxicity Study in the Rat with a 15 Day Treatment-Free Period. Sequani Study Number: JSK0016; and a Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test in the Rat with Extension to Evaluate Sexual Maturation of F1 Generation. Envigo Study Number: S56037). The high dose level of 1000 mg/kg/day selected is the limit dose for this type of study and this dose level was expected to produce some toxicity, such as a reduction in body weight gain or food intake, but not excessive lethality that would prevent meaningful evaluation. The mid-dose level selected was 300 mg/kg/day, which was the approximate geometric mean between the high and low dose, was expected to produce minimal to moderate toxicity. The low dose level of 100 mg/kg/day was selected with the expectation that it would produce no observable indications of toxicity.

- Rationale for animal assignment (if not random):
Allocation to groups was performed using a stratified randomisation procedure based on individual body weights recorded on Day 0 of gestation by the supplier (ensuring that females mated with the same male were spread across the groups).

- Fasting period before blood sampling for (rat) dam thyroid hormones: No, animals were not fasted prior to blood sampling.

- Time of day for (rat) dam blood sampling: Day 20 of gestation between 08.00 and 09.00 hours

- Other:
- Justification for route of administration: P1400 is an industrial chemical and the route of administration corresponds to a possible route of human exposure during manufacture, use or handling.

- Justification for species selected: The rat is a suitable rodent species, acceptable to regulatory authorities and for which extensive background data are available.

Animals were dosed once daily from Day 6 to Day 19 of gestation, inclusive, by gavage, using a rubber catheter and disposable syringe at a constant dose volume of 4 mL/kg body weight. Individual doses were adjusted according to the most recently recorded body weight.
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: examined twice daily for mortality and morbidity

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical examination daily. From the start of dosing, animals were observed approximately.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded on Day 0 of gestation by the supplier. At the CRO, body weights were recorded daily from Day 5 to Day 20 of gestation, inclusive.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes / No / No data
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
The amount of food consumed by each animal was recorded over Days 6 to 9, 9 to 12, 12 to 15, 15 to 18 and 18 to 20 of gestation.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: Major organs were examined at necropsy. Gravid uterus and placenta weights were recorded and organs or tissues showing any macroscopic abnormalities were removed and retained in fixative. Liver and thyroids were weighed after trimming of fat and other contiguous tissue and the thyroids were weighed together after fixation.

HISTOPATHOLOGY
For all animals, the liver and thyroids were preserved in 10 % buffered formalin, wax embedded, cut at a nominal thickness of 4 μm to 5 μm, stained with haematoxylin and eosin
and examined microscopically.

Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes

Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

For all pregnant females, the number of corpora lutea and the number and distribution of implantations in each uterine horn were recorded. Implantations were classified as early
intrauterine deaths, late intrauterine deaths, dead foetuses or live foetuses. The implantations were numbered separately for the right and left horns. Numbering was sequential, commencing at the ovarian end through to the cervix. The foetuses and their placentae were removed and the uterus and ovaries were retained in 10 % buffered formalin.
Blood sampling:
- Serum: Yes
- Volume collected : 0.2 mL

Blood samples (0.2 mL) were taken from the tail vein into gel separator tubes and allowed to clot for at least 30 minutes at room temperature. All animals were sampled on Day 20 of gestation between 08.00 and 09.00 hours. Animals were not fasted prior to blood sampling and were sampled in a random cage order.

All samples were centrifuged (3000 g, 10 minutes, at approximately 4°C) and the resultant serum was aliquoted into two tubes, where possible (Aliquot 1 contained 50 μL and Aliquot 2 contained all remaining serum) and stored frozen (< -70°C) until analysis.

Aliquot 1 samples were analysed for thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH), using a commercially available analytical kit and analysed on the
Luminex MAGPIX. Aliquot 2 samples were retained frozen (< -70 °C) until satisfactory results were obtained.
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: half per litter
- Anogenital distance of all live rodent pups: Yes, anogenital distance was measured using digital callipers, measuring between the anus and caudal end of the genital tubercle

On Day 20 of gestation, live foetuses were killed by rapid cooling, weighed, sexed and examined for external abnormalities. Anogenital distance was measured using digital callipers, measuring between the anus and caudal end of the genital tubercle.

Approximately 50 % of the live foetuses were allocated to the fixed head examination. All foetuses were briefly placed in 70 % IDA and subjected to micro-dissection, where the viscera were examined and the foetuses eviscerated. The foetuses allocated to the fixed head examination were decapitated and the heads fixed in Bouin's fluid and examined by serial sectioning.

All carcasses were transferred to 95 % IDA. The carcasses of the intact foetuses were cleared in potassium hydroxide, stained with Alizarin red S and Alcian blue to visualise the ossified skeleton and cartilage and examined. The headless carcasses were discarded without further examination, following confirmation from the Sponsor, after examination of the intact skeletons.

Structural congenital abnormalities that impair, or potentially impair, the survival or constitution of the foetus were classified as major abnormalities. Abnormalities that in isolation, do not impair the survival or constitution of the foetus but could potentially interfere with normal bodily function were classified as minor abnormalities. Alternative structures occurring regularly in the control population, which may be permanent or transient, were classified as variants.

Foetuses with major external or visceral abnormalities were photographed.
Statistics:
Data were processed to give group mean values and standard deviations, where appropriate. Where the data allowed, the following methods were used for statistical analysis, comparing Groups 2, 3 and 4 against Group 1.

Depending on the nature of the data set that was to be analysed, appropriate tests were applied, as indicated in Table 2. Where parametric tests were appropriate, they were preceded by a check for homogeneity of variance using the Levene test and, where available, the Shapiro-Wilks test for normality. If either of these two assumptions failed, a log transformation was applied before retesting. If the transformation failed, appropriate non-parametric tests were applied.

The percentage of foetuses affected were treated as continuous non-parametric data, without trend analysis, using Kruskal-Wallis and Wilcoxon tests. The number of litters affected were analysed, without trend analysis, using Chi-Squared and Fisher Exact test. Probability values of less than 5 % were regarded as providing sufficient evidence to reject the null hypothesis and therefore statistical significance was identified at the p<0.05 level. For illustrative purposes, significance levels of p<0.01 and p<0.001 were also noted. Further details can be found in Table no. 2.
Indices:
1) Pre-implantation loss (%) = ((no. of corpora lutea – no. of implantation sites) / (no. of corpora lutea)) x 100

2) Post-implantation loss (%) = ((no. of implantation sites – no. of live foetuses) / (no. of implantation sites) x 100

3) Anogenital distance index (ACGI) = (Anogenital distance (mm) / cubed root body weight (g))
Historical control data:
Historical Control Data (HCD) presented in Appendix 13 of the final study report.
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
No treatment-related clinical signs were observed at doses up to 1000 mg/kg/day. Clinical signs recorded, such as hair staining and/or loss and scabbing, were considered not to be toxicologically significant as they were present for only a few days and were also noted in the control animals.
Dermal irritation (if dermal study):
not examined
Mortality:
no mortality observed
Description (incidence):
No mortality was observed through the study period.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Body weight, body weight gain, terminal body weight adjusted for the weight of the gravid uterus was observed to be similar in all groups and unaffected by treatment.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
Food consumption remained unaffected by treatment.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Endocrine findings:
no effects observed
Description (incidence and severity):
A slight, non-statistically significant increase in group mean total T3 concentration was observed at 1000 mg/kg/day when compared with the corresponding controls. However, most of the individual T3 concentrations were within, or only slightly outside the historical control data range. No effect of treatment was observed on T4 or TSH concentrations.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
There was no effect of treatment on thyroid gland weight. Mean liver weight relative to body weight was statistically significantly higher than corresponding controls in female rats given 300 mg/kg/day and 1000 mg/kg/day (p≤0.05 and p≤0.001, respectively). At 300 mg/kg/day, individual values remained within the limits of the historical control range but at 1000 mg/kg/day, there were four animals with liver weight marginally above the upper limit of the range. However, mean liver weight adjusted for body weight was only 9 % higher than controls, and since there were no pathological changes in the liver, these increases were considered not to be an adverse treatment-related effect but represented an adaptive response.
Gross pathological findings:
no effects observed
Description (incidence and severity):
Gross necropsy did not reveal any remarkable treatment-related findings. A variety of spontaneous findings was observed in treated animals with no indication of an effect of treatment. The spectrum of these findings was generally consistent with changes encountered in rats of this strain and age kept under laboratory conditions.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
No microscopic findings in the liver or thyroid considered to be related to the test material. A variety of spontaneous findings was observed in treated animals with no indication of an effect of treatment. The spectrum of these findings was generally consistent with changes encountered in rats of this strain and age kept under laboratory conditions.
Histopathological findings: neoplastic:
not examined
Other effects:
not examined
Number of abortions:
no effects observed
Description (incidence and severity):
No abortions observed.
Pre- and post-implantation loss:
no effects observed
Description (incidence and severity):
There was no effect of treatment on the incidence of pre- implantations loss and post-implantation loss.
Total litter losses by resorption:
no effects observed
Description (incidence and severity):
No resorptions observed.
Early or late resorptions:
no effects observed
Description (incidence and severity):
No resorptions observed.
Dead fetuses:
no effects observed
Description (incidence and severity):
No dead feotuses
Changes in pregnancy duration:
not examined
Changes in number of pregnant:
no effects observed
Description (incidence and severity):
On Day 20 of gestation there were 20, 20, 21, and 20 females with live foetuses in the groups given 0, 100, 300 or 1000 mg/kg/day, respectively.
Other effects:
no effects observed
Description (incidence and severity):
There was no effect on the numbers of corpora lutea or number of live foetuses.
Key result
Dose descriptor:
NOAEL
Effect level:
ca. 1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Basis for effect level:
other: Systemic toxicity
Fetal body weight changes:
effects observed, treatment-related
Description (incidence and severity):
At 1000 mg/kg/day, mean foetal weight was slightly, but statistically significantly lower, than control (p≤0.05). Individual values were within, or only marginally lower than the lower limit of the historical control data range and therefore, this slight decrease was considered not to be an adverse effect of treatment.
Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
There was no effect on the number of live foetuses.
Changes in sex ratio:
no effects observed
Description (incidence and severity):
There was no effect on the foetal sex ratio.
Changes in litter size and weights:
no effects observed
Anogenital distance of all rodent fetuses:
no effects observed
Description (incidence and severity):
Foetal anogenital distance was not affected by treatment with the test material.
Changes in postnatal survival:
no effects observed
External malformations:
effects observed, non-treatment-related
Description (incidence and severity):
Major foetal abnormalities were noted in one foetus in each of the groups given 100 mg/kg/day (Interventricular septum, incomplete) and 300 mg/kg/day (Cervical vertebra; one or more neural arch, malformed), and in two foetuses from two litters in the group given 1000 mg/kg/day (Interventricular septum, incomplete; Head, dome shaped). There were no major foetal abnormalities noted in the control group. The nature, incidence, and intergroup distribution of these major foetal abnormalities were considered to be incidental and not treatment-related as they are commonly observed in the historical control data and were only seen in single litters and single foetuses.
Skeletal malformations:
effects observed, treatment-related
Description (incidence and severity):
At 1000 mg/kg/day, there were statistically significantly higher numbers of litters with foetuses displaying minor or variant abnormalities of the skull that included incomplete ossification of the squamosal, nasal, jugal and/or occipital (p≤0.05, p≤0.01). However, the incidences of these findings were within, or only slightly outside, the historical control ranges. Additionally, there were increased incidences of foetuses showing the minor abnormality of incomplete ossification of one or more neural arches of the sacral vertebrae (p≤0.001) and the variant findings of non-ossification of the 5th and 6th sternebrae (p≤0.01). The incidences of these findings were within, or only slightly higher than the historical control ranges. These incidences of slightly lower foetal skeletal ossification were considered to be associated to the slightly lower foetal weight observed in this group, and therefore, were considered to be non-adverse.
Visceral malformations:
effects observed, non-treatment-related
Key result
Dose descriptor:
NOAEL
Effect level:
ca. 1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Developmental toxicity
Key result
Developmental effects observed:
no

The mean concentrations of 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester in test formulations analysed for the study were within 5% of nominal concentrations which was within the acceptance criteria, confirming accurate formulation. The coefficient of variation values were less than 5 %, which was within the applied limits, confirming the precision of analysis.No test material was detected in control formulations.

Table 3. Results of Formulation analysis

Occasion

Group

Nominal

concentration

(mg/mL)

Analyzed concentration (mg/mL)

RME (%)

CV (%)

Procedural

Recoveries (%)

Top

Middle

Bottom

Mean

First

occasion

1

0

-

ND, ND

-

-

-

-

-

2

25

25.4

25.0

24.9

25.1

+0.4

1.05

100.0

3

75

77.8

72.0

73.5

74.4

-0.8

4.02

98.6

4

250

245

245

243

244

-2.4

0.41

98.4

 

Last

occasion

1

0

-

ND, ND

-

-

-

-

-

2

25

26.1

25.5

25.7

25.8

+3.2

1.15

104.3

3

75

78.1

77.8

78.3

78.1

+4.1

0.37

106.3

4

250

261

263

263

262

+4.8

0.45

104.1

RME Relative mean error, representing the deviation from nominal

ND Not detected

CV Coefficient of variation

Table 4. Thyroid hormone assessment (Group mean values)

Group

 

Mean Total

T3 (ng/mL)

Mean Total

T4 (ng/mL)

Mean Total

TSH (ng/mL)

(#)

(#)

(# 1)

Group 1

(Control – 0 mg/kg/day)

Mean

18.693

373.439

1.610

SD

8.464

23.998

0.822

N

20

20

19

Trend

 

 

Group 2

(P1400

100 mg/kg/day)

Mean

18.941

391.337

1.337

SD

7.235

40.834

1.030

N

20

20

19

 

 

Group 3

(P1400

300 mg/kg/day)

Mean

17.140

365.278

1.813

SD

7.838

34.829

0.917

N

21

21

20

 

 

Group 4

(P1400

1000 mg/kg/day)

Mean

23.332

367.309

1.566

SD

7.857

37.235

0.842

N

20

20

19

Trend

>0.05

>0.05

>0.05

(#) - Williams, Anova & Dunnett

(#1) - Williams, Anova & Dunnett(Log)

Table 5. Organ weights: Absolute and Relative to Body Weight (Group mean values)

Group

 

Liver

(g)

Adjusted

Liver %

Liver Wt

Body Weight

(#)

(# 1)

(#)

Group 1

(Control – 0 mg/kg/day)

Mean

12.530

12.363

5.098

SD

0.995

-

0.280

N

20

20

20

Trend

 

 

Group 2

(P1400

100 mg/kg/day)

Mean

12.145

12.283

5.064

SD

1.166

-

0.301

N

20

20

20

Trend

-

>0.05

>0.05

 

 

Group 3

(P1400

300 mg/kg/day)

Mean

12.661

12.774

5.267

SD

1.429

-

0.276

N

21

21

21

Trend

>0.05

≤0.05*

≤0.05*

 

 

Group 4

(P1400

1000 mg/kg/day)

Mean

13.612

13.522

5.577

SD

1.112

-

0.331

N

20

20

20

Trend

≤0.01**

≤0.001***

≤0.001***

(#) - Williams, Anova & Dunnett: * = p ≤ 0.05; ** = p ≤ 0.01; *** = p ≤ 0.001

(#1) - Williams, Ancova/Anova & Dunnett: * = p ≤ 0.05; *** = p ≤ 0.001

{Covariate(s): Adjusted Bodyweight [Rodent]}

Table 6. Pregnancy Data (Summary)

Sex: Female

Group 1

(Control – 0 mg/kg/day)

Group 2

(P1400

100 mg/kg/day)

Group 3

(P1400

300 mg/kg/day)

Group 4

(P1400

1000 mg/kg/day)

Group Size

 

22

22

22

22

Not pregnant

 

2

2

1

2

Not pregnant %

 

9.1

9.1

4.5

9.1

Not pregnant Died/Killed

Sum

0

0

0

0

Not pregnant Schedule Kill

Sum

2

2

1

2

Pregnant

 

20

20

21

20

Pregnant %

 

90.9

90.9

95.5

90.9

Pregnant Died/Killed/Aborted

Sum

0

0

0

0

Pregnant with Total Resorption

Sum

0

0

0

0

Number with Live Foetuses

Sum

20

20

21

20

Table 7. Uterine and Implantation Data (Group mean values)

Sex: Female

Group 1

(Control – 0 mg/kg/day)

Group 2

(P1400

100 mg/kg/day)

Group 3

(P1400

300 mg/kg/day)

Group 4

(P1400

1000 mg/kg/day)

Number with Live Foetuses (GD 20)

 

20

20

21

20

Number of Corpora Lutea (#)

Sum

228

229

243

236

Mean

11.4

11.5

11.6

11.8

SD

1.3

2.1

1.5

1.0

Trend

-

-

>0.05

Number of Implantations (#1)

Sum

213

202

230

218

Mean

10.7

10.1

11

10.9

SD

1.0

2.9

1.4

1.9

Trend

-

-

>0.05

% Pre-implantation Loss (#1)

Mean

6.0

12.9

5.0

8.0

Trend

-

-

>0.05

Number of Early Deaths (#1)

Sum

15

13

12

20

Mean

0.8

0.7

0.6

1.0

SD

1.2

0.9

0.9

1.6

Trend

-

-

>0.05

Number of Late Deaths (#)

Sum

0

1

0

1

Mean

0.0

0.1

0.0

0.1

SD

0.0

0.2

0.0

0.2

Trend

-

-

>0.05

Number of Dead Foetuses

Sum

0

0

0

0

Mean

0.0

0.0

0.0

0.0

SD

0.0

0.0

0.0

0.0

Number of Live Foetuses (#)

Sum

198

188

218

197

Mean

9.9

9.4

10.4

9.9

SD

1.6

3.2

1.6

1.9

Trend

-

-

>0.05

% Post-implantation Loss (#)

Mean

7.2

8.2

5.1

8.8

Trend

-

-

>0.05

Live Foetuses as % of Implants

Mean

92.8

91.8

94.9

91.2

(#) - Williams, Anova & Dunnett(Log) (#1) - Shirley, Kruskal-Wallis & Steel

Table 8. Litter weights (g) / Foetal data (Group mean values)

Sex: Female

Group 1

(Control – 0 mg/kg/day)

Group 2

(P1400

100 mg/kg/day)

Group 3

(P1400

300 mg/kg/day)

Group 4

(P1400

1000 mg/kg/day)

Number with Live Foetuses

 

20

20

21

20

Number of Live Foetuses

Sum

198

188

218

197

No of Male Foetuses

Sum

100

111

104

98

No of Female Foetuses

Sum

98

77

114

99

% of Male Foetuses (#)

Mean

50.8

60.0

47.5

49.6

Trend

-

-

>0.05

Litter Weight (#1)

Mean

37.9

35.64

38.48

35.05

Trend

-

-

>0.05

Foetal Weight (M+F) (#2)

Mean

3.86

3.91

3.71

3.55

Trend

-

>0.05

≤0.05*

Foetal Weight (M)

Mean

3.97

4.00

3.82

3.63

Foetal Weight (F)

Mean

3.76

3.76

3.63

3.47

Placental Weight (#2)

Mean

0.50*

0.54

0.48

0.52

Trend

-

-

>0.05

(#) - Williams, Anova & Dunnett(Log)

(#1) - Williams, Anova & Dunnett

(#2) - Shirley, Kruskal-Wallis & Steel: * = p ≤ 0.05


Table 9. Examination of foetuses (number of foetuses examined)

Sex: Female

Group 1

(Control – 0 mg/kg/day)

Group 2

(P1400

100 mg/kg/day)

Group 3

(P1400

300 mg/kg/day)

Group 4

(P1400

1000 mg/kg/day)

Litters Examined

N

20

20

21

20

External Foetuses Examined

Sum

198

188

218

197

Visceral Foetuses Examined

Sum

198

188

218

197

Visc Head Foetuses Examined

Sum

98

95

105

97

Skeletal Foetuses Examined

Sum

98

95

105

97

Skel Skull Foetuses Examined

Sum

98

95

105

97

Bouins Head Foetuses Examined

Sum

100

93

113

100

Brain Foetuses Examined

Sum

98

95

105

97

Table 10. Examination of foetuses (Overall summary)

 

Group 1

(Control – 0 mg/kg/day)

Group 2

(P1400

100 mg/kg/day)

Group 3

(P1400

300 mg/kg/day)

Group 4

(P1400

1000 mg/kg/day)

Number of Foetuses Examined:

198

188

218

197

Number of Litters Examined:

20

20

21

20

All classifications

 

 

     Number of Foetuses

 

112

109

119

114

     Group % of Foetuses

 

56.6

58.0

54.6

57.9

     Number of Litters [#]

N+ve

20

20

21

20

 

%

100.0

100.0

100.0

100.0

     Litter % of Foetuses [#1]

Mean

56.37

59.72

54.82

58.14

 

Major

 

 

     Number of Foetuses

 

0

1

1

2

     Group % of Foetuses

 

0.0

0.5

0.5

1.0

     Number of Litters [#]

N+ve

0

1

1

2

 

%

0.0

5.0

4.8

10.0

     Litter % of Foetuses [#1]

Mean

0.00

1.00

0.53

1.13

 

Minor

 

 

     Number of Foetuses

 

24

48

37

45

     Group % of Foetuses

 

12.1

25.5

17.0

22.8

     Number of Litters [#]

N+ve

12*

18*

19*

18*

 

%

60.0

90.0

90.5

90.0

     Litter % of Foetuses [#1]

Mean

12.73*

26.39**

17.61*

23.23**

[#] - Chi-Squared & Fisher's Exact: * = p ≤ 0.05

[#1] - Kruskal-Wallis & Wilcoxon: * = p ≤ 0.05; ** = p ≤ 0.0


Conclusions:
Based on the lack of adverse treatment-related effects observed at the highest dose tested, the maternal and developmental toxicity NOAEL for 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester in the rat was determined to be 1000 mg/kg/day.
Executive summary:

A key OECD Guideline 414 study in rats was conducted to evaluate the effects of the test material (1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester (alternative name: Santicizer® Platinum 1400)) on the embryonic and foetal development of the rat when administered from Day 6 to Day 19 of gestation, inclusive.

 

The test material was administered to groups of sexually mature, timed-mated, female Crl:WI(Han) rats (22/dose) once daily via oral gavage in a corn oil vehicle at 0, 100, 300, or 1000 mg/kg/day from Day 6 to Day 19 of gestation, inclusive. All females were observed daily from the start of dosing and body weight and food intake were recorded at regular intervals. Blood samples for thyroid hormone assessment were obtained on the day of necropsy. Animals were killed on Day 20 of gestation, a necropsy was performed and the internal organs were examined for macroscopic abnormalities, and selected organs were weighed and examined microscopically. The progress and outcome of pregnancy were assessed and maternal dead body weight, gravid uterus and placenta weights were recorded. The foetuses were removed from the uterus, weighed, sexed and examined for external, visceral, skeletal and cartilage abnormalities.

 

No mortality or clinical signs of treatment-related toxicity were observed through the study period and there was no effect of treatment on body weight or food intake at any dose level. Thyroid hormone (T3, T4, & TSH) concentrations were unaffected by exposure to the test material at any dose level.

 

Gross necropsy did not reveal any remarkable treatment-related findings and microscopic evaluation did not reveal any treatment-related findings in the liver or thyroid. At 300 and 1000 mg/kg/day, a non-adverse increase in mean liver weight compared with control animals was observed while there was no effect on thyroid weight.

 

There was no effect on the numbers of corpora lutea, implantations, the incidence of pre-implantations loss, post-implantation loss or on the number of live foetuses. Foetal weight was observed to be slightly lower than that of corresponding controls at 1000 mg/kg/day. However, individual values were within, or only marginally lower than the lower limit of the historical control data range and therefore, this slight decrease was considered not to be an adverse effect of treatment. There was no effect on foetal sex ratio, placental weight, or foetal anogenital distance.

 

Slight increases in minor and variant foetal abnormalities of incomplete or non-ossification of some skull bones, vertebral neural arches and sternebrae were observed at 1000 mg/kg/day. These were associated with the lower foetal weights in this group compared with control animals rather than a direct effect of treatment and considered to resolve postnatally.

 

Based on the results observed the maternal and developmental toxicity NOAEL for 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester in the rat was determined to be 1000 mg/kg/day.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
One key Guideline substance specific study in rodents available for assessment.
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

A key OECD Guideline 414 study (Sequani Limited, 2021) in rats was conducted to evaluate the effects of the test material (1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester (alternative name: Santicizer® Platinum 1400)) on the embryonic and foetal development of the rat when administered from Day 6 to Day 19 of gestation, inclusive.

 

The test material was administered to groups of sexually mature, timed-mated, female Crl:WI(Han) rats (22/dose) once daily via oral gavage in a corn oil vehicle at 0, 100, 300, or 1000 mg/kg/day from Day 6 to Day 19 of gestation, inclusive. All females were observed daily from the start of dosing and body weight and food intake were recorded at regular intervals. Blood samples for thyroid hormone assessment were obtained on the day of necropsy. Animals were killed on Day 20 of gestation, a necropsy was performed and the internal organs were examined for macroscopic abnormalities, and selected organs were weighed and examined microscopically. The progress and outcome of pregnancy were assessed and maternal dead body weight, gravid uterus and placenta weights were recorded. The foetuses were removed from the uterus, weighed, sexed and examined for external, visceral, skeletal and cartilage abnormalities.

 

No mortality or clinical signs of treatment-related toxicity were observed through the study period and there was no effect of treatment on body weight or food intake at any dose level. Thyroid hormone (T3, T4, & TSH) concentrations were unaffected by exposure to the test material at any dose level.

 

Gross necropsy did not reveal any remarkable treatment-related findings and microscopic evaluation did not reveal any treatment-related findings in the liver or thyroid. At 300 and 1000 mg/kg/day, a non-adverse increase in mean liver weight compared with control animals was observed while there was no effect on thyroid weight.

 

There was no effect on the numbers of corpora lutea, implantations, the incidence of pre-implantations loss, post-implantation loss or on the number of live foetuses. Foetal weight was observed to be slightly lower than that of corresponding controls at 1000 mg/kg/day. However, individual values were within, or only marginally lower than the lower limit of the historical control data range and therefore, this slight decrease was considered not to be an adverse effect of treatment. There was no effect on foetal sex ratio, placental weight, or foetal anogenital distance.

 

Slight increases in minor and variant foetal abnormalities of incomplete or non-ossification of some skull bones, vertebral neural arches and sternebrae were observed at 1000 mg/kg/day. These were associated with the lower foetal weights in this group compared with control animals rather than a direct effect of treatment and considered to resolve postnatally.

 

Based on the lack of adverse treatment-related effects observed at the highest dose tested, the maternal and developmental toxicity NOAEL for 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2-(phenylmethyl) ester in the rat was determined to be 1000 mg/kg/day.

A key Guideline 422 study was conducted to evaluate the effects of repeated oral (gavage) administration of the test material (P1400: 1,2-Cyclohexanedicarboxylic Acid, 1-butyl 2 (phenylmethyl) ester, CAS 1200806-67-2) to rats during a four-week period in F0 males two weeks before mating through a minimum of 28 days (after confirming female pregnancy), until day 20 postpartum for females including the day before sacrifice, and from birth to sexual maturation (PND 70) in F1 pups. 12 rats per sex per dose received the test material in corn oil once daily via oral gavage at does of 150, 300, or 600 mg/Kg/day while the control animals received corn oil only (Envigo CRS, 2018a).

 

Animals were observed twice daily for mortality and for any clinical signs following administration of the test material. Parameters such as body weight, food consumption, behavioural assessments such as grip strength, motor activity, and sensory reactivity assessment were evaluated for. Additionally, blood samples were extracted from the retro-orbital plexus of all animals under light isoflurane anesthesia and clinical biochemistry as well as haematology assessments were undertaken. Blood samples were taken from all surviving adult males, at termination and from all surviving dams on day 21 postpartum for thyroid hormone analysis. At necropsy, post-mortem examination of the external surface of the body, all orifices, cranial, thoracic and abdominal cavities and their contents with emphasis on the uterus (females only), number of implantation sites (females only) was performed. Organ weights were recorded and all organ and tissue samples (except for the nose) of selected animals from the control and high dose groups (5 animals/sex) were processed, embedded, cut at an approximate thickness of 2-4 micrometers and stained with hematoxylin and eosin. Reproductive organs of all control and high dose animals as well as of animals selected for sexual maturation were also examined. Histopathological analysis was undertaken and slides of organs and tissues collected at necropsies of all animals to be evaluated, except for the bone marrow smear for which no test was planned, were examined by the pathologist. Additionally, based on treatment-related morphological changes detected in thyroids in high-dose animals, this organ from the other treatment group animals were examined in all adult animals. A qualitative staging of spermatogenesis and histopathology evaluation of interstitial cells of all males from the control and high-dose groups was also performed.

 

No treatment-related mortality, clinical signs (other than salivation) or effects on functional observation battery were observed in the parental generation. There was no effect on body weights during the study and there was no indication of an effect on food consumption during the treatment period. The statistically significant increases noted at 300 and 600 mg/Kg/day in males (postnatal days 8 and 15) or in females at 600 mg/kg/day on gestation day 14 were not considered to have been toxicologically relevant given their magnitude (no more than 1.2 times the Control mean values), as it was transient and as there were no effects in body weights that could be associated with it. Haematology, coagulation and clinical biochemistry effects observed, in the absence of a dose-effect relationship (neutrophil and basophils) or given that the differences were only observed in one sex (protein and globulin values in males), were not considered to be toxicologically relevant. Gross necropsy did not reveal any remarkable findings and all findings were considered to be incidental and unrelated to treatment with the test material. Reproductive parameters of pre-coital, fertility or gestation length or index were unaffected by treatment. There were no effects on survival, litter size, sex ratio and no adverse effect on offspring growth. No adverse effects were observed in the reproductive organs relating to alterations in the sexual maturation.

 

In parental males, a dose-related increase in mean kidney weights, correlating to an increase in the amount of hyaline droplets, was observed at histopathological examination. However, this was considered to be within the normal historical range for rats of this strain and age. At 600 mg/kg/day in parental animals, there were no histopathological findings that correlate with the increased liver and spleen weights in males or in the decrease in uterus, cervix and oviducts in females. A minimal or slight hypertrophy of the follicular epithelium of the thyroid glands was observed in males and females of all treated groups (150, 300 and 600 mg/kg/day). This finding could be considered to be within the normal variation in females at 150 and 300 mg/kg/day due to the low incidence recorded (2/12 at 150 mg/kg/day and 1/11 at 300 mg/kg/day), and the lack of effects in the T4 determinations. The decrease observed in T4 in parental males at 600 mg/kg/day also correlated with the histopathological findings.

 

For the F1 generation, no changes in body weights or food consumption, clinical or necropsy signs were observed which were indicative of a reaction to the test material. There were no changes in the mean weights of the thyroids or parathyroids. In males, there was a dose-related increase in the incidence and/or severity of follicular cell hypertrophy in thyroid glands. The decrease in T4 and increase observed in TSH the PND 70 males at 600 mg/kg/day also correlated with the histopathological findings. In females, minimal hypertrophy of the follicular epithelium in the thyroid glands was observed in a few animals treated at 600 mg/kg/day (3 affected females from 30 observed).

 

Based on the results observed, the systemic toxicity No Observed Adverse Effect Level (NOAEL) in males and females rats was determined to be 600 mg/kg/day. At this dose level, histological findings (minimal to slight microscopic changes in the thyroid glands) observed were considered non-adverse in the absence of consistent changes in hormone levels. At 600 mg/kg/day, thyroid hormone changes were observed. However, given that the mechanism leading to these changes is unknown, and in the absence of effects on reproductive performance, their relevance to humans is uncertain and could be therefore, considered non-adverse.

 

Based on lack of adverse treatment-related effects observed, the NOAEL for reproductive / developmental toxicity was determined to be 600 mg/kg/day.

Justification for classification or non-classification

P1400 does not meet the criteria for classification as a reproductive/developmental toxicant under EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Additional information