Pentadecan-15-olide

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

From 2002-03-12 to 2002-08-03

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study performed according to OECD test guideline No. 415 and in compliance with GLP. The study was fully reliable (Klimisch score = 1), however the reliability score was lowered to 2 which is the maximum score for read-across. The supporting substance is considered adequate for read-across purpose (see Iuclid section 13 for justification).

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 415 [One-Generation Reproduction Toxicity Study (before 9 October 2017)]

Deviations:

yes

Remarks:

age at study initiation not reported

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP Compliance Program (2002-12-02)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

A mixture of: (E)-oxacyclohexadec-12-en-2-one; (E)-oxacyclohexadec-13-en-2-one; a) (Z)-oxacyclohexadec-(12)-en-2-one and b) (Z)-oxacyclohexadec-(13)-en-2-one

EC Number:

422-320-3

EC Name:

A mixture of: (E)-oxacyclohexadec-12-en-2-one; (E)-oxacyclohexadec-13-en-2-one; a) (Z)-oxacyclohexadec-(12)-en-2-one and b) (Z)-oxacyclohexadec-(13)-en-2-one

IUPAC Name:

422-320-3

Test material form:

other: viscous liquid

Details on test material:

- Name of test material (as cited in study report): ST 01 C 02
- Physical state: colourless viscous liquid
- Storage condition of test material: stored under Nitrogen at ~4°C in the dark

Test animals

Species:

rat

Strain:

other: Sprague-Dawley Crl: CD (SD) IGS BR strains

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
- Source: Charles River (UK) Limited, Manston Road, Margate, Kent- UK
- Age at study initiation: no data
- Weight at study initiation: (P) Males: 190-256 g; Females: 207-276
- Fasting period before study: none
- Housing: Upon arrival, the animals were housed in groups of four in polypropylene cages with stainless steel grid floors and tops, suspended over paper-lined polypropylene trays. During the mating period animals were transferred to a similar type cage on a one male to one female per cage basis. Following evidence of successful mating, the males were returned to their original cages and transferred to a separate animal room of comparable conditions. The females were housed, individually, in polypropylene cages with solid floors and stainless steel tops. Mated females were given softwood chips, as bedding throughout gestation and lactation.
- Diet (e.g. ad libitum): ad libitum (pelleted Rat and Mouse VRF1C Diet (Charles River UK Limited, Margate, Kent))
- Water (e.g. ad libitum): ad libitum
- Acclimation period: males: 17 days, females: 31 days (during which health status was assessed)


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2
- Humidity (%): 55 ± 15
(On isolated occasions the room temperature and/or humidity fell outside the protocol target limits but this was considered not to have affected the purpose or integrity of the study)
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: 2002-03-12 To: 2002-08-03

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Test material was prepared at the appropriate concentration as a solution in 0.5% carboxymethyl cellulose (vehicle). For each dose level a separate aliquot of test material was weighed into the appropriate container. The vehicle was added and mixed using a Silverson homogeniser to ensure a homogeneous suspension was formed.

VEHICLE
- Justification for use and choice of vehicle (if other than water): test compound of low solubility in water
- Dose volume: 5 mL/kg bw

Details on mating procedure:

- M/F ratio per cage: 1 (1 female + 1 male per cage)
- Length of cohabitation: until evidence of successful mating (up to three weeks)
- Proof of pregnancy: The presence of sperm within the vaginal smear and/or vaginal plug in situ was taken as positive evidence of mating
- After successful mating each pregnant female was caged (how): Following evidence of successful mating, mated females were separated from male and housed individually during the period of gestation and lactation. The males were returned to their original cages and transferred to a separate animal room of comparable conditions.
- Any other deviations from standard protocol: none

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of each formulation were taken once per week during the first four weeks and approximately once every month until study completion and analysed for achieved concentration of test material at Safepharm Analytical Laboratory.

The concentration of test material in the test material formulations was determined by gas chromatography (GC) using an external standard technique. Analysis of homogeneity, stability & concentrations in formulations gave good results, as shown hereafter:
HOMOGENEITY: The test material formulations were mixed thoroughly and samples were taken from the top, middle and bottom of the container, shaking in between sampling. Sampling was performed in triplicate. Measured concentrations were: 91.9-93.6%, 84.8-93.4% and 94-99% of nominal concentrations for 10, 50, 200 mg/mL nominal concentrations respectively.
STABILITY: The test material formulations were sampled and analysed initially and then after storage at approximately +4°C in the dark for 14 days. Measured concentrations were >96 % of nominal concentrations of 10, 50 and 200 mg/mL.
TEST MATERIAL FORMULATIONS: the test material formulations were sampled and analysed within weeks (Week 1, 2, 3, 4, 8, 12 & 16) of preparation. Ranges of concentrations expressed in % of nominal concentration were 89-108%, 83-109% and 81-104% for the nominal concentrations of 10, 50 & 200 mg/mL respectively. Corresponding mean concentrations were 97%, 98 & 95 % for 10, 50 & 200 mg/mL nominal concentrations. The results indicate that the prepared formulations were within acceptable limits of the nominal concentration.

Duration of treatment / exposure:

(P) males: 72 days before mating, then like females
(P) Females: 16 days before mating / up to 20 days during mating (until evidence of mating)/ 21 days (until weaning, or as near to this date as possible)

Frequency of treatment:

Daily, 7 days each week

Details on study schedule:

Male animals were dosed for 72 days and female animals were dosed for 16 days, at their appointed dose levels, prior to pairing.
Parental males and females were paired within their respective dose groups for up to twenty one days.
Following evidence of mating, the animals were separated and males returned to their holding cages.
The pregnant females were allowed to deliver their offspring. The offspring were observed for growth and development during lactation.
At weaning on Day 21 (or as near to this date as possible) post partum the surviving offspring were killed and examined macroscopically post mortem.
The surviving adult Parental animals were killed and examined macroscopically post mortem.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 20, 250 & 1000 mg/kg bw/day (P, m/f)
Basis:
actual ingested

No. of animals per sex per dose:

28 animals/sex/dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The concentrations tested in this study were determined from a subchronic 90-day oral toxicity study (OECD 408 Guideline) performed with the same test material on the same rat strain and for which a NOEL of 1000 mg/kg bw/day was determined.

Positive control:

Not used

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily during the normal week and once daily during week-end.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily, immediately before, immediately after and one hour after dosing


BODY WEIGHT: Yes
- Time schedule for examinations: weekly during maturation and mating period. Following mating the parental males were weighed weekly until termination. Parental generation females showing evidence of mating were weighed on days 1, 4, 7, 14 and 21 post coitum. Parental generation females with a live litter were weighed on Days 1, 4, 7, 14 and 21 post partum.


FOOD CONSUMPTION:
During the maturation periods food consumption was recorded for each cage of parental generation adults. For parental generation females showing evidence of mating, food consumption was recorded for the periods covering days 1 to 7, 7 to 14 and 14 to 21 post coitum. For parental generation females with live litters, food consumption was recorded for the periods covering Days 1 to 7 and 7 to 14 postpartum.

Oestrous cyclicity (parental animals):

NA

Sperm parameters (parental animals):

Not Applicable/Not required in OECD 415 Guideline.
(P) males: weight of: epididymides, prostate, seminal vesicles (with coagulating gland), testes were determined.

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no


PARAMETERS EXAMINED
The following parameters were examined in offspring: Number and sex of pups, bodyweight/weight gain, stillbirths, live births, postnatal mortality, clinical signs, physical or behavioural abnormalities, physical development (detachment of pinna, tooth eruption, eye opening), reflexes (surface righting reflex, mid-air righting reflex, startle reflex and pupil reflex). For the time of observations, see Table 8.5.1/2 in "Any other information on material and methods including tables"


GROSS EXAMINATION OF DEAD PUPS:
yes, all offspring that died, or were killed in extremis during the lactation period were examined macroscopically and externally.

Postmortem examinations (parental animals):

All adult animals, killed in extremis or found dead during the course of the study, were examined macroscopically for internal and external abnormalities. All significant abnormalities were retained in fixative for possible further study.

SACRIFICE
- All animals: All surviving animals following successful weaning of offspring, including non-fertile animals

GROSS NECROPSY
All animals were examined macroscopically for both internal and external abnormalities. Selected organs and tissues were retained in fixative.

HISTOPATHOLOGY / ORGAN WEIGHTS
Organ weights were determined for: Epididymides, Ovaries, Pituitary gland, Prostate, Seminal vesicles (with coagulating gland), Testes, Uterus with cervix.
Histopathology was performed on: Cervix, Coagulation gland, Epididymides, Pituitary gland, Prostate, Seminal vesicles, Significant abnormalities, Testes, Uterus, Vagina, Ovaries. (Initially the tissues from high dose and control animals were processed and embedded in paraffin wax BP (mp 56°C). Sections of the tissues were taken at 5µm thickness, mounted on glass slides and stained with haematoxylin and eosin. In addition, any significant abnormalities from all dose groups were similarly processed. The sections of reproductive and target organs from control and high dose animals were examined microscopically by a pathologist).

Postmortem examinations (offspring):

All offspring were examined macroscopically for internal and external abnormalities.

SACRIFICE
- The F1 offspring were sacrificed at 21 days of age.
- These animals were subjected to postmortem macroscopic examinations for internal and external abnormalities.

Statistics:

The following parameters were analysed statistically, where appropriate using the test methods outlined as follows:
Adult male and female bodyweight during the maturation, gestation and lactation periods, adult male food consumption, female food consumption during maturation, gestation and lactation, litter size, litter weight, individual offspring bodyweight, offspring landmarks of physical development.
Adult precoital intervals, female gestation lengths, offspring reflexological responses and litter sex ratios: Individual values were compared using the Kruskal-Wallis non-parametric rank sum test. Where significant differences were seen, pairwise comparison of control values against treated group values was performed using Mann-Whitney "U" test.
Histopathology: Chi-squared analysis for differences in the incidence of lesions occurring with an overall frequency of 1 or greater. Kruskal-Wallis one-way non-parametric analysis of variance for the comparison of severity grades for the more frequently observed conditions.

Reproductive indices:

For each group the following were calculated.
Pre-coital interval: calculated as the time elapsing between initial pairing and the observation of positive mating?
Mating Index % = number of animals mated/number of animals paired * 100.
Pregnancy index % = Number of pregnant females / Number of animals mated * 100.
Gestation length: calculated as the number of days of gestation including the days for observation of mating at the start of parturition. When the start of parturition occurred overnight, the total was adjusted by substracting half a day.
Parturition index % = Number of females delivering live pups / Number of pregnant females * 100.

Offspring viability indices:

The following indices were calculated for each group from individual data.
Live birth index = Number of pups alive on Day 1 / Number of pups born * 100.
Viability Index 1 (%) = Number of pups alive on Day 4/Number of pups alive on Day 1 * 100.
Viability Index 2 (%) = Number of pups alive on Day 7/Number of pups alive on Day 4 * 100.
Viability Index 3 (%) = Number of pups alive on Day 14/Number of pups alive on Day 7 * 100.
Viability Index 4 (%) = Number of pups alive on Day 21/Number of pups alive on Day 14 * 100.
Viability Index 5 (%) = Number of viable pups at weaning/Number of pups alive on Day 1 * 100.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
Mortality:
At 1000 and 50 mg/kg bw/d there were no mortalities during the course of the study.
At 250 mg/kg bw/d two males were found dead during the mating/post mating phase of the study. There was no significant clinical history. Post mortem examination showed macroscopic changes in the lungs of both animals that were consistent with dosing trauma.

Clinical signs:
At 1000 mg/kg bw/d there was evidence of increased salivation, predominantly post dosing for males and females. For males only, there was increased salivation pre-dosing which was at a lower incidence and frequency compared to post-dosing salivation. All other clinical findings were those commonly observed on this type of study.
At 250 mg/kg bw/d approximately half of the males showed evidence of increased salivation immediately post dosing. The incidence and frequency were lower than was seen at the highest dose level. Only one female showed similar findings. There were no other significant clinical findings.
At 50 mg/kg bw/d two males, but no females, showed evidence of increased salivation immediately post dosing. There were no other significant clinical findings for this group.


BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
- Maturation: there were no significant treatment-related effects upon male or female bodyweight gain and food consumption during the course of the maturation phase of the study.
- Gestation & Lactation: there were no significant treatment-related effects upon female bodyweight gain and food consumption during gestation and lactation


REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
- Fertility and Mating Performance: there were no significant treatment-related effects upon mating performance or fertility. The intergroup distribution of precoital intervals showed that the majority of pairings resulted in positive evidence of mating within four days after pairing.
- Gestation and Parturition: There were no significant treatment-related effects upon pregnancy or parturition. The intergroup distribution of gestation lengths was comparable.


ORGAN WEIGHTS (PARENTAL ANIMALS)
There were no significant treatment-related differences in group mean organ weights, both as absolute values or relative to bodyweight, for either males or females.

GROSS PATHOLOGY (PARENTAL ANIMALS)
There were no significant treatment-related macroscopic findings for males or females. The findings observed were those commonly encountered in this type of study.

HISTOPATHOLOGY (PARENTAL ANIMALS)
There were no significant treatment-related histopathological changes. The findings were those commonly observed in this type of study, or were otherwise incidental.

Effect levels (P0)

Dose descriptor:

NOAEL

Remarks:

fertility

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Details on results (F1)

VIABILITY (OFFSPRING)
There were no significant treatment-related effects upon litter size at birth and subsequent offspring viability during lactation.

CLINICAL SIGNS (OFFSPRING)
There were· no significant treatment-related effects upon offspring clinical condition throughout lactation; as indicated by comparable incidence and severity of clinical findings observed.

BODY WEIGHT and DEVELOPMENT (OFFSPRING)
There were no significant treatment-related effects upon individual offspring weight gain and physical development during lactation.
At 1000 mg/kg bw/d the mean offspring weight was higher than control values at Day 1 post partum. The difference was statistically significant (p<0.01) but this was considered to be a chance result and not related to treatment. At the same dose level, the group mean time to completion of incisor eruption was lower than control values which was statistically significant (p<0.01). This is also considered to be unrelated to treatment.

GROSS PATHOLOGY (OFFSPRING)
There were no significant treatment-related differences in the type and incidence of macroscopic post mortem findings for offspring that died during the course of lactation or for offspring at terminal necropsy.

REFLEXOLOGICAL RESPONSE:
There were no significant treatment-related effects upon offspring reflexological responses

SEX RATIO: There were no significant treatment-related effects upon offspring sex ratios at birth or weaning. At 250 mg/kg bw/d the percentage males per litter at Days 1 and 21 post partum was higher than control values which was statistically significant (p<0.05). This was considered to be unrelated to
treatment.

Effect levels (F1)

Dose descriptor:

NOAEL

Remarks:

growth, development and viability

Generation:

F1

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

DISCUSSION: During the in-life phase of the study there was no evidence of significant toxicity to the adult. The clinical observation of increased salivation, predominantly post dosing is a reflex reaction to the oral administration of an unpleasant-tasting test material and may not represent a toxic response. The two male mortalities during the study were likely to be the consequence of dosing trauma. The mortalities were considered not to be a result of test material toxicity.

 

There were no treatment-related effects seen on the fertility and reproductive performance of male or female rats, as shown by the high pregnancy rate for all treatment groups, and in the lack of significant differences in the distribution of precoital intervals and gestation lengths for all dose groups. There were no significant treatment effects upon offspring during the study. The live litter size of offspring at birth and their subsequent viability during the lactation phase was comparable to controls. The growth and physical development of offspring during gestation and lactation was not affected by the test material as evidenced by the comparable mean individual offspring weight after birth and subsequent bodyweight gain. There were isolated incidents of differences in the age of onset of landmarks of physical development There were no treatment- related trends and the isolated nature of the differences clearly suggests that they were not related to treatment. There were no significant treatment-related effects on intra-litter offspring sex ratios. Statistically significant differences were not treatment or dosage-related.

 

The post mortem macroscopic evaluations showed no treatment-related effects on adults or offspring. The macroscopic findings seen on this study are those commonly observed for adults and offspring in this type of study. There were no significant effects on selected organ weights for adult males or females. Histopathology showed no treatment-related effects upon the reproductive organs of either sex.

Applicant's summary and conclusion

Conclusions:

There were no effects upon reproductive organs or fertility and reproductive performance. There were no effects upon offspring viability, growth and development during gestation and lactation.
The No Observed Adverse Effect Level (NOAEL) for fertility and offspring development is therefore ≥ 1000 mg/kg bw/d.

Executive summary:

In a one-generation reproduction toxicity study performed in accordance with OECD test guideline No. 415 and in compliance with GLP, the test material diluted in carboxymethylcellulose (CMC) was administered orally, by gavage, to groups of twenty-eight male and twenty-eight female Sprague-Dawley Crl: CD (SD) IGS BR strains rats throughout maturation, mating, gestation and lactation. The dose levels were 50, 250 and 1000 mg/kg bw/d with a similar sized control group receiving vehicle alone.

Following at least ten and two weeks of dosing respectively, male and female rats were paired within their dose groups to produce litters. At weaning of the offspring, all surviving animals were killed and examined macroscopically.

Parental animals were observed daily for clinical signs. Bodyweights and food consumption were recorded weekly during the maturation phase which was continued for males after the mating phase. Mated females were weighed and food consumption recorded on specific days post coitum and post partum.

The offspring were observed daily for clinical signs. The litter size and individual pup bodyweights were recorded on specific days post partum. During the lactation period, the offspring were observed for intra-litter onset and duration of landmarks or physical development. On specific days of lactation, reflexological assessment of offspring was performed.  

Post mortem macroscopic examinations were performed on all adults and offspring, including decedents. Reproductive and potential target organs were weighed from all parental animals and were then preserved in fixative. Histopathology was carried out on reproductive and target organs from control and high dose groups parental animals.

 

For all dose levels, particularly 250 mg/kg bw/d and above, there was evidence of increased salivation. The incidence and frequency were dosage related. The finding is considered not to be a result of test material toxicity but an adaptive response to the oral administration of an unpleasant tasting material.

There were no significant treatment-related effects upon adults during the course of the study.

There were no significant treatment-related effects upon adult fertility or reproductive performance.

There were no treatment-related effects on litter size at birth. Subsequent offspring viability during lactation was unaffected by treatment.

Offspring growth and development, during lactation was unaffected by treatment. Differences in intra-litter sex ratios were not related to treatment.

Macroscopic evaluations showed no significant treatment-related effects upon adults or offspring. There were no effects upon selected adult organ weights or histopathology.

 

The administration of the test material to male and female rats throughout one reproductive cycle at dose levels up to 1000 mg/kg bw/d resulted in no evidence of significant toxicity to adults.

There were no effects upon reproductive organs or fertility and reproductive performance. There were no effects upon offspring viability, growth and development during gestation and lactation.

The No Observed Adverse Effect Level (NOAEL) for fertility and offspring development is therefore ≥ 1000 mg/kg bw/d.

 

Under the test conditions, the test material is not classified according to the annex VI of the Regulation (EC) No. 1272/2008 (CLP) and of the Directive 67/548/EEC.

This study is acceptable and satisfies the requirement for reproductive toxicity endpoint.

The supporting substance is considered adequate for read-across purpose (see Iuclid section 13 for justification).