Registration Dossier

Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
May - Nov 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Version / remarks:
29 Jul 2016
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
(from the competent authority) Landesamt für Umwelt Rheinland-Pfalz
Limit test:
no

Test material

Constituent 1
Test material form:
solid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Batch No.of test material: 7070141023
- Expiration date of the Batch: Jul 2021
- Content: 81.3 g/100 g (100 g/100 g - Neopentyl glycol (5.9 g/100 g) - water (12.8 g/100 g))
- Physical state / appearance: solid / black

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: ambient; avoid temperatures < 0 °C
- Stability under test conditions: The stability of the test substance in deinoized water was demonstrated for a period of 7 days at room temperature.

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test substance preparations in deionized water were prepared in intervals, which took into account the analytical results of the stability verification. The test substance preparations were produced weekly, at least. For the preparation of the administration suspensions the test substance was weighed in a calibrated beaker depending on the dose group, topped up with deionized water and mixed with a magnetic stirrer.

FORM AS APPLIED IN THE TEST (if different from that of starting material) : suspension

Test animals

Species:
rat
Strain:
Wistar
Remarks:
Crl:WI (Han)
Details on species / strain selection:
The test guidelines require the rat to be used as the animal species. This rat strain was selected since extensive historical control data are available for Wistar rats.
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Males 70 - 76 days, Females about 77 - 90 days
- Weight at study initiation: The weight variation of the animals used did not exceed 20 percent of the mean weight of each sex.
- Housing: During pretreatment, the rats were housed together (up to 5 animals per sex and cage) in Polysulfonate cages. During the study period, the rats were housed individually in Polycarbonate cages with the following exceptions: During overnight matings, male and female mating partners were housed together in Polycarbonate cages; Pregnant animals and their litters were housed together until PND 13 in Polycarbonate cages.
- Diet (e.g. ad libitum): ground Kliba maintenance diet mouse / rat "GLP" meal, supplied by Provimi Kliba SA, Kaiseraugst, Switzerland; ad libitum
- Water (e.g. ad libitum): drinking water was supplied from water bottles; ad libitum
- Acclimation period: 21 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
deionized
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test substance preparations in deionized water were prepared in intervals, which took into account the analytical results of the stability verification. The test substance preparations were produced weekly, at least.
For the preparation of the administration suspensions the test substance was weighed in a calbrated beaker depending on the dose group, topped up with deionized water and mixed with a magnetic stirrer.
Details on mating procedure:
- M/F ratio per cage: 1 : 1
- Length of cohabitation: max. 2 weeks
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): individually
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analytical verifications of the stability of the test substance in deionized water for a period of 7 days at room temperature were carried out prior to the start of the administration period.
At the beginning (during premating), twice during gestation and once during lactation of the study each 3 samples were taken from the lowest and highest concentration for potential homogeneity analyses. The 3 samples were withdrawn from the top, middle and bottom of the preparation vessel. These samples were used as a concentration control at the same time. At the above-mentioned time points, additionally, one sample from the mid concentration was taken for concentration control analysis. Of each sample, one additional reserve sample (described by the suffix "R") was retained.
The samples collected at the beginning and during lactation period were analyzed in the Analytical Laboratory. Additionally, the reserve samples of the highest concentration collected at the end of the study (lactation period) and samples of the highest concentration collected at the end of gestation period were analyzed. All further samples were not analyzed and stored frozen (at - 20 °C) in the Laboratory of the Mechanistic Toxicology until the finalization of the study.
Duration of treatment / exposure:
The duration of treatment covered a 2 weeks premating period and mating period in both sexes (mating pairs were from the same dose group), approximately 3 days post-mating in males, the entire gestation period, up to 13 days of the lactation period in females as well as up to one day prior to the day of schedule sacrifice of animals.
Frequency of treatment:
once daily at approximately the same time in the morning
Doses / concentrationsopen allclose all
Dose / conc.:
120 mg/kg bw/day (nominal)
Remarks:
corresponds to 105 mg/kg bw/d main ingredient (content of the main test compound is 87.2 % including 5.9% neopentyl glycol)
Dose / conc.:
350 mg/kg bw/day (nominal)
Remarks:
corresponds to 305 mg/kg bw/d main ingredient (content of the main test compound is 87.2 % including 5.9% neopentyl glycol)
Dose / conc.:
1 150 mg/kg bw/day (nominal)
Remarks:
corresponds to 1003 mg/kg bw/d main ingredient (content of the main test compound is 87.2 % including 5.9% neopentyl glycol)
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The doses were selected by request of the sponsor. The oral route was selected since administration by gavage has been proven to be appropriate for the detection of a toxicological hazard.
- Rationale for animal assignment (if not random): The animals were distributed according to weight among the individual test groups, separated by sex.
- Fasting period before blood sampling for clinical biochemistry: yes, feed was withdrawn for about 16 - 20 hours

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: A cageside examination was conducted at least daily for any signs of morbidity, pertinent behavioral changes and signs of overt toxicity before the administration as well as within 2 hours and within 5 hours after the administration. Abnormalities and changes were documented daily for each animal. The parturition and lactation behavior of the dams was generally evaluated in the mornings in combination with the daily clinical inspection of the dams. On weekdays (except Saturday, Sunday and public holidays) the parturition behavior of the dams was inspected in the afternoons in addition to the evaluations in the mornings. The day of parturition was considered the 24-hour period from about 15.00 h of one day until about 15.00 h of the following day.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations (DCO) were performed in all animals once prior to the first administration (day 0) and at weekly intervals during the administration period. The examinations started in the morning. The findings were ranked according to the degree of severity, if applicable. For observation, the animals were removed from their cages by the investigator and placed in a standard arena.
- The following parameters listed were assessed: Abnormal behavior in "handling", fur, skin, posture, salivation, respiration, activity / arousal level, tremors, convulsions, abnormal movements, gait abnormalities, lacrimation, palpebral closure, exophthalmos, assessment of the feces discharged during the examination (appearance / consistency), assessment of the urine discharged during the examination, pupil size

BODY WEIGHT: Yes
- Time schedule for examinations: In general, the body weight of the female parental animals was determined once a week at the same time of the day (in the morning) until sacrifice. The body weight change of the animals was calculated from these results. The following exceptions are notable for the female parental animals: During the mating period the parental females were weighed on the day of positive evidence of sperm (GD 0) and on GD 7, 14 and 20. Females with litter were weighed on the day of parturition (PND 0) and on PND 4, 7, 10 and 13. Females without positive evidence of sperm, without litter or waiting for necropsy, were weighed weekly. These body weight data were solely used for the calculations of the dose volume.

FOOD CONSUMPTION: Yes
- Time schedule: Generally, food consumption was determined once a week for male and female parental animals, with the following exceptions: Food consumption was not determined after the 2nd premating week (male parental animals) and during the mating period (male and female F0 animals). Food consumption of the F0 females with evidence of sperm was determined on gestation days (GD) 0 - 7, 7 - 14, and 14 - 20. Food consumption of F0 females which gave birth to a litter was determined on PND 1 - 4, 4 - 7, 7 - 10, 10 - 13. Food consumption was not determined in females without positive evidence of sperm during the mating and the gestation period and in females without litter during the lactation period.

WATER CONSUMPTION: Yes
- Time schedule for examinations: Generally, water consumption was determined once a week for the male and female parental animals over a period of 3 days. Water consumption was not determined after the 2nd premating week (male parental animals) and during the mating period (male and female parental animals). Water consumption of the females with evidence of sperm was determined for GD 0 - 3, 7 - 10 and 14 - 17. Water consumption of the females which gave birth to a litter was determined for PND 1 - 4, 4 - 7, 7 - 10 and 10 - 13. Water consumption was not determined in the females without positive evidence of sperm during mating and gestation periods and in the females without litter during lactation period.

OTHER: mortality, functional observational battery (FOB), motor activity measurement
Oestrous cyclicity (parental animals):
For all females of the pool estrous cycle normality was evaluated before the beginning of the administration period.
Estrous cycle length was evaluated by daily analysis of vaginal smear for all F0 female parental rats for a minimum of 2 weeks prior to mating. Determination was continued throughout the pairing period until the female exhibited evidence of copulation. At necropsy, an additional vaginal smear was examined to determine the stage of estrous cycle for each F0 female with scheduled sacrifice.
Sperm parameters (parental animals):
Parameters examined in male parental generations:
testis weight, epididymis weight, prostate weight
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, anogenital distance (AGD), pup weight on the day of AGD, presence of nipples/areolae in male pups

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals were sacrificed by decapitation under isoflurane anesthesia on study day 30.
- Maternal animals: All surviving animals were sacrificed by decapitation under isoflurane anesthesia on PND 14.

GROSS NECROPSY
- Gross necropsy consisted of gross pathology, special attention being given to the reproductive organs.

HISTOPATHOLOGY / ORGAN WEIGHTS
- The following weights were determined in all animals sacrificed on schedule:
1. Anesthetized animals (final body weight)
2. Epididymides
3. Ovaries
4. Prostate (ventral and dorsolateral part together, fixed)
5. Seminal vesicles with coagulating glands (fixed)
6. Testes
7. Thyroid glands (with parathyroid glands) (fixed)
8. Uterus with cervix
- The following weights were determined in 5 animals per sex / test group sacrificed on schedule:
1. Adrenal glands (fixed)
2. Brain
3. Heart
4. Kidneys
5. Liver
6. Spleen
7. Thymus (fixed)
- The following organs or tissues of all parental animals were fixed in 4 % neutral buffered formaldehyde solution or in modified Davidson's solution: all gross lesions, adrenal glands, aorta, bone marrow (femur), brain, cecum, cervix, coagulating glands, colon, duodenum, esophagus, epididymides (modified Davidson's solution), extraorbital lacrimal glands, eyes with optic nerve (modified Davidson's solution), femur with knee joint, heart, ileum, jejunum (with Peyer's Patches), kidneys, larynx, liver, lungs, lymph nodes (axillary and mesenteric), mammary gland (male and female), nose (nasal cavity), ovaries (modified Davidson's solution), oviducts, pancreas, parathyroid glands, pharynx, pituitary gland, prostate, rectum, salivary glands (mandibular and sublingual), sciatic nerve, seminal vesicles, skeletal muscle, spinal cord (cervical, thoracic and lumbar cord), spleen, sternum with marrow, stomach (forestomach and glandular stomach), testes (modified Davidson's solution), thymus, thyroid glands, trachea, urinary bladder, uterus, vagina
- The eyes with optic nerve and ovaries of the animals that sacrificed intercurrently were fixed in 4 % neutral buffered formaldehyde solution
Postmortem examinations (offspring):
SACRIFICE
- The F1 offspring were sacrificed at PND 13.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations

HISTOPATHOLOGY / ORGAN WEIGTHS
The following tissues were prepared for microscopic examination and weighed, respectively: thyroid glands, parathyroid glands
Statistics:
- DUNNETT-test (two-sided): food consumption (F0), water consumption (F0), body weight and body weight change (F0, F1), gestation days, anogenital distance, anogenital index
- FISHER'S EXACT test (one-sided): male and female mating indices, male and female fertility indices, females mated, females delivering, gestation index (females with liveborn pups), females with stillborn pups, females with all stillborn pups
- WILCOXON test (one-sided+) with BONFERRONI-HOLM adjustment: mating days until day 0 pc, % postimplantation loss, pups stillborn, % perinatal loss, nipple development
- WILCOXON test (one-sided-) with BONFERRONI-HOLM adjustment: implantation sites, pups delivered, pups liveborn, live pups day x, viability index, survival index
- WILCOXON test (two-sided): % live male day x, % live female day x
- KRUSKAL-WALLIS test (two-sided): number of cycles and cycle length, rearing, grip strength of forelimbs and hindlimbs, landing foot-splay test, motor activity, weight parameters
Reproductive indices:
male mating index (%)
male fertility index (%)
female mating index (%)
female fertility index (%)
gestation index (%)
live birth index (%)
postimplantation loss (%)
Offspring viability indices:
viability index (%)
survival index (%)
sex ratio
anogenital index

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
During the entire study period (from premating day 2 onwards) black discolored feces were observed in all male and female animals of test group 2 and 3 (350 and 1150 mg/kg bw/d). Furthermore all animals of test group 3 showed grey discolored skin at the entire body from premating day 7 onwards. These findings were considered to be related to treatment, caused by the color of the test compound, and therefore assessed as being not adverse. One female animal of test group 2 (No. 130, 350 mg/kg bw/d) showed semiclosed eyelids, pale skin, piloerection, unsteady gait and hypothermia on gestation day 21, the day before delivery. Since these findings were gone on the next day after delivery it seems obvious that these were caused by problems with littering and therefore not treatment-related.

Detailed clinical observations
In all males and females of test group 3 (1150 mg/kg bw/d) discolored skin and discolored feces were observed from day 7 onwards. In test group 2 (350 mg/kg bw/d) all animals showed discolored feces from day 7 onwards. These findings were considered to be treatment-related but not adverse. One female animal (No. 130) of test group 2 additionally showed semiclosed eyelids, pale skin, piloerection, unsteady gait and hypothermia on study day 35 which was the day before delivery. These isolated findings were considered to be caused by problems with littering since they were gone after littering. All male and female animals in test group 1 (120 mg/kg bw/d) did not show any alterations.
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, non-treatment-related
Description (incidence):
One female animal (No. 133) of test group 3 (1150 mg/kg bw/d) was sacrificed moribund on gestation day 6 due to clinical findings such as hypothermia, poor general condition, unsteady gate, slightly labored respiration, piloerection, vaginal discharge and heavy discoloration of skin and eyes (black). Considering the heavy discoloration of the animal and the pathology observations the findings were assessed to be caused by a gavage error.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Mean body weights of all male and female F0 generation parental animals in all test substance-treated groups were comparable to the concurrent control values during the entire study period.
Body weight changes are staggering throughout all dose groups, partly increased and partly decreased. Since there is no dose-effect relationship showing up this was considered to be not treatment related and non adverse.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
Food consumption of the F0 animals in all test groups was not influenced by the treatment throughout the entire study period.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
effects observed, non-treatment-related
Description (incidence and severity):
In male animals of test group 3 (1150 mg/kg bw/d) water consumption was significantly increased from premating day 0 to 3 (21.4 %) and a slight (non-statistically significant) increase was still observed from premating day 7 to 10 (16.2 %). Males of test group 2 (350 mg/kg bw/d) showed slightly (non-statistically significant) increased water consumption from premating day 0 to 3 (16.4 %) as well as males of test group 1 (120 mg/kg bw/d) on premating days 0 to 3 (13.0 %) and 7 to 10 (18.4 %). In females of test group 2 a slight (non-statistically significant) increase of water consumption was observed from premating day 7 to 10 (13.4 %). During gestation slightly (non-statistically significant) increased water consumption was observed in test group 3 on days 7 to 10 (13.5 %) and 14 to 17 (12.1 %) whereas animals of test group 1 showed reduced water consumption from day 14 to 17 (- 12 %). In animals of test group 2 increased (non-statistically significant) water consumption was observed on lactation days 4 to 7, 7 to 10 and 10 to 13 (11.5 %, 12 % and 26.5 %) as well as in animals of test group 3 on lactation days 7 to 10 (12.1 %).
The increase of water consumption after the start of administration in the premating phase showed a dose-dependency in the values between day 0 and 3. Afterwards, no clear dose-dependency was given at later time points. Therefore, for the alterations at the beginning of administration it cannot be excluded that the alterations were treatment-related. However, because of temporary occurrence of the alterations in dose-dependency, they were assessed as non-adverse. Due to the sporadic occurrence without dose-dependency, the alterations in water consumptions at later time points during the administration period were considered to be spontaneous in nature and independent of treatment.
Ophthalmological findings:
not examined
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
No treatment-related, adverse changes among hematological parameters were observed.
At the end of the administration period, in males of test groups 2 and 3 absolute neutrophil cell counts were significantly decreased. Total white blood cell (WBC) counts and absolute lymphocyte counts were also lower in these individuals, although not statistically significantly. WBC and absolute lymphocyte counts in both mentioned test groups and absolute neutrophil cell counts in test group 2 were within historical control ranges, whereas the absolute neutrophil count mean in males of test group 3 was marginally below this range (males, total WBC 4.50 - 7.04 Giga/L; absolute lymphocytes 3.38 - 5.96 Giga/L; absolute neutrophils 0.73 - 1.44 Giga/L). In females, no changes of the differential blood cell counts were observed. Therefore, the mentioned changes in males of test groups 2 and 3 were regarded as incidental and not treatment-related.
Clinical biochemistry findings:
effects observed, non-treatment-related
Description (incidence and severity):
No treatment-related changes among clinical chemistry parameters were observed.
In dams at lactational day 14, sodium levels were significantly increased, but the mean was only marginally above the historical control range (females, sodium 132.9 - 139.8 mmol/L) and this was the only changed electrolyte value. Therefore, this alteration was regarded as incidental and not treatment-related.
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
- Home cage observations: No test substance-related or spontaneous findings were observed in male and female animals of all test groups during the home cage observation.
- Open field observation: In the open field observations each one male animal of test group 2 (350 mg/kg bw/d; No. 23) and test group 3 (1150 mg/kg bw/d; No. 32) showed grey discolored urine. This finding was considered to be treatment-related but not adverse. Concerning all other animals the open field observations did not reveal any test substance-related findings in male and female animals of all test groups.
- Sensorimotor tests / reflexes: There were no test substance-related findings in male and female animals of all test groups.
- Quantitative parameters: There were no test substance-related findings in male and female animals of all test groups.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Treatment-related findings were observed in the kidneys of males and females.
In test group 3 males and females, a minimal to moderate degeneration / regeneration of proximal convoluted tubules was noted and was associated with an intracellular basophilic granular pigmentation (minimal to slight). In test group 2 males and females, only a minimal accumulation of basophilic pigmentation occurred. No pigmentation was detected in test group 1. A special stain proved that the nature of these granular basophilic pigmentation was not a dystrophic mineralization (von Kossa stain negative). The pigmentation seen in the kidneys by light microscopy might be directly correlated to the test substance but it cannot be further characterized chemically by histopathological methods.
The female of test group 3, sacrificed in a moribund state (No. 133) showed a severe tubular necrosis accompanied by a severe basophilic pigmentation not only in cortical tubular cells but also in the lumina of cortical, medullar and papillary tubules. In addition, basophilic emboli were found in glomerular capillaries and interstitial vessels. In the lungs, basophilic emboli of the same nature as described in the kidneys were detected in the venules. In the heart, a slight hemorrhage was noted at the base of the heart, around the great vessels and partly in the myocardium, accompanied here by a minimal focal necrosis. The lesions in the base of the heart and the black effusion in the thoracic cavity found at gross pathology are assumed to be the result of a gavage error.
All other findings occurred either inidvidually or were biologically equally distributed over control and treatment groups. They were considered to be incidental or spontaneous in origin and without any relation to treatment.
The stages of spermatogenesis in the testes of males of the high dose test group were comparable to those of the controls. In high dose females the different stages of functional bodies in the ovaries were present and comparable to the control animals.
The female animal No. 129, which was not pregnant as well as the male mating partner No. 29 did not show relevant histopathological findings that could have impaired the fertility.
Histopathological findings: neoplastic:
no effects observed
Other effects:
no effects observed
Description (incidence and severity):
Motor activity measurement (MA)
No treatment-related changes on motor activity data (summation of all intervalls) were observed in all male and female animals of all dose groups in comparison to the concurrent control group. In female animals of test group 3 (1150 mg/kg bw/d) a significantly increase of beam interruptions was recorded for interval 4, 5 and 8. Furthermore in test group 2 (350 mg/kg bw/d) a significantly decrease of beam interruptions was recorded for interval 2 as well as in test group 1 (120 mg/kg bw/d) for interval 12. These isolated single findings in test group 1 - 3 without any effect on the respective sum of all intervals, were assessed as incidental and spontaneous in nature.

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Description (incidence and severity):
Estrous cycle data revealed regular cycles in the parental females of all test groups including the control.
The mean estrous cycle duration in the different test groups 0, 1, 2 and 3 (0, 120, 350 and 1150 mg/kg bw/d) was 3.9 days. The mean number of cycles in the different test groups ranged from 2.8 to 3.0.
Reproductive function: sperm measures:
not examined
Reproductive performance:
not examined

Details on results (P0)

- The male mating index was 100 % in test groups 0, 1 and 3. In test group 2 the male mating index was 90 % due to male No. 29 mated with female No. 129 without evidence of sperm within the mating period.
- Fertility was proven for nearly all of the F0 parental males within the scheduled mating interval to produce F1 litter with exception of one male in test group 2. This male of test group 2 (No. 129 mated with female No. 129) did not generate implants in utero. The male fertility index was 100 % in test groups 0, 1 and 3 and 90 % in test group 2. Thus, the test substance did not affect fertility of the F0 generation parental males.
- The female mating index calculated after the mating period for F1 litter was 100 % in test groups 0, 1 and 3 and 90 % in test group 2. One female (No. 129) of test group 2 showed no evidence of sperm within the scheduled mating period. The mean duration until sperm was detected (GD 0) was 2.4, 2.2, 4.8, 2.7 days in test groups 0 - 3. This finding reflected the normal range of biological variation inherent in the strain of rats used for this study as all respective values were within the range of the historical control data.
- All sperm positive rats got pregnant. The female fertility index was 100 % in all test groups. The mean duration of gestation was similar in all test groups (22.1 days in test group 0; 21.9 days in test group 1; 22.0 days in test group 2; 22.2 days in test group 3). These findings reflected the normal range of biological variation inherent in the strain of rats used for this study as all respective values were within the range of the historical control data.
- The gestation index was 90 % in the control group and 100 % in all treated groups.
- The rate of live birth indices were 99.1 % in test group 0, 98.3 % in test group 1, 100 % in test group 2 and 97.1 % in test group 3. There was 1 stillborn pup recorded in control group (0.9 %), 2 stillborn pups recorded in test group 1 (1.7 %) and 3 stillborn pups recorded in test group 3 (2.9 %). The values of test groups 1, 2 and 3 reflected the normal range of biological variation inherent in the strain of rats used for this study as all respective values were within the range of the historical control data (pups liveborn 91.7 - 100 %, pups stillborn 0.0 - 8.3 %). Thus, the test substance did not affect fertility, reproduction and delivery of the F0 generation parental females.
- The postimplantation loss was 11.5 % in test group 0, 0 % in test group 1, 6.2 % in test group 2 and 10.6 % in test group 3. These findings reflected the normal range of biological variation inherent in the strain of rats used for this study as all respective values were within the range of the historical control data (0.0 - 18.1 %).

Effect levels (P0)

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
1 150 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks:
corresponds to 1003 mg/kg bw/d main ingredient (content of the main test compound is 87.2 % including 5.9% neopentyl glycol)
Sex:
male/female
Basis for effect level:
other: no treatment-related adverse systemic findings
Remarks on result:
other: reproductive performance and fertility
Dose descriptor:
NOAEL
Effect level:
350 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks:
corresponds to 305 mg/kg bw/d main ingredient (content of the main test compound is 87.2 % including 5.9% neopentyl glycol)
Sex:
male/female
Basis for effect level:
organ weights and organ / body weight ratios
Remarks on result:
other: general systemic toxicity

Target system / organ toxicity (P0)

Critical effects observed:
yes
Lowest effective dose / conc.:
1 150 mg/kg bw/day (nominal)
System:
urinary
Organ:
kidney
Treatment related:
yes
Dose response relationship:
yes
Relevant for humans:
not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
There were no test substance-related, adverse clinical signs observed in any of the F1 generation pups of the different test groups.
In control group one pup, test group 1 three pups and test group 3 six pups were not assessed (died) on one day due to being stillborn, found dead or missing (cannibalized). These findings were assessed as incidental and spontaneous in nature.
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, non-treatment-related
Description (incidence and severity):
The pup mortality was based on total number of stillborn pups, dead pups, pups sacrificed moribund and cannibalized pups. The numbers appeared to be dose-dependent but, with a maximum of 2.9 % stillborn pups and a minimum of 96.3 % in viability index, were well in the range of historical control data (0.0 - 8.3 % and 89.4 - 100 %).
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Mean body weights and body weight change of all male and female pups of all test groups were comparable to the concurrent control values throughout the entire lactation period.
One male runt in test group 1 and test group 2 and one female runt in control group were seen.
Food consumption and compound intake (if feeding study):
not examined
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
Urinalysis findings:
not examined
Sexual maturation:
not examined
Anogenital distance (AGD):
no effects observed
Description (incidence and severity):
Neither in anogenital distance nor in anogenital index treatment-related effects were noted in all F1 male and female pups of all test groups.
Nipple retention in male pups:
no effects observed
Description (incidence and severity):
The apparent number and percentage of male pups having areolae was not influenced by the test substance when examined on PND 13.
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
A few F1 pups showed spontaneous findings at gross necropsy, such as post mortem autolysis, discolored testis and dilated renal pelvis. Three pups were not assessed because those were missing (cannibalized). These findings occurred without any relation to dosing and are considered to be spontaneous in nature.
Histopathological findings:
not examined
Other effects:
effects observed, non-treatment-related
Description (incidence and severity):
Pup number and status at delivery
The mean number of delivered F1 pups per dam and the rates of liveborn, stillborn, found dead and cannibalized F1 pups were evenly distributed among the test groups. The respective values reflect the normal range of biological variation inherent in the strain used in this study.

Pup viability index / mortality
The viability index indicating pup survival during early lactation (PND 0 - 4) was 100 %, 99.3 %, 100 % and 96.3 % in test groups 0, 1, 2 and 3, respectively, showing no alteration related to the treatment. The survival index indicating pup mortality on PND 4 - 13 was 100 % in all test groups (0, 1, 2 and 3).

Sex ratio
The sex distribution and sex ratios of live F1 pups on the day of birth and PND 13 did not show substantial differences between the control and the test substance-treated groups; slight differences were regarded to be spontaneous in nature.

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not examined

Details on results (F1)

Regarding developmental toxicity, no adverse finding of toxicity was observed in male or female pups of all test groups investigating up to the nominal dose of 1150 mg/kg bw/d.

Effect levels (F1)

Dose descriptor:
NOAEL
Generation:
F1
Effect level:
1 150 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no treatment-related adverse systemic findings
Remarks on result:
other: developmental toxicity

Target system / organ toxicity (F1)

Critical effects observed:
no

Overall reproductive toxicity

Reproductive effects observed:
no

Any other information on results incl. tables

Table 1: Male fertility indices for F0 males

 

Test group 0
(0 mg/kg bw/d)

Test group 1
(120 mg/kg bw/d)

Test group 2
(350 mg/kg bw/d)

Test group 3
(1150 mg/kg bw/d)

Male fertility index [%]

100

100

90

100

* p0.05; ** p0.01

Table 2: Sex ratio of live F1 pups

PND 0

Test group 0
(0 mg/kg bw/d)

Test group 1
(120 mg/kg bw/d)

Test group 2
(350 mg/kg bw/d)

Test group 3
(1150 mg/kg bw/d)

Live males [%]

48.8

56.6

51.4

54.7

Live females [%]

51.2

43.4

48.6

45.3

PND 13

 

 

 

 

Live males [%]

50.8

51.7

50.0

50.8

Live females [%]

49.2

48.3

50.0

49.2

* p ≤ 0.05; ** p ≤ 0.01

Table 3: Absolute organ weights of F0 parental animals

 

Male animals

Test group

(mg/kg bw/d)

1

(120)

2

(350)

3

(1150)

Kidneys

+2.83%

+13.58%*

+20.58%**

*p <= 0.05; **p <= 0.01

Table 4: Relative organ weights of F0 parental animals

 

Male animals

Female animals

Test group

(mg/kg bw/d)

1

(120)

2

(350)

3

(1150)

1

(120)

2

(350)

3

(1150)

Kidneys

+4.46%

+15.14%*

+21.49%**

+2.98%

+8.20%

+18.06%**

*p <= 0.05; **p <= 0.01

Table 5: Histopathology of F0 parental animals

 

Male animals

Female animals

Test group (mg/kg bw/d)

0 (0)

1 (120)

2 (350)

3 (1150)

0 (0)

1 (120)

2 (350)

3 (1150)

No. of animals

10

10

10

10

10

10

10

10

Degeneration / regeneration, tubules, mf

0

0

0

10

0

0

0

9

-      Grade 1

 

 

 

1

 

 

 

1

-      Grade 2

 

 

 

5

 

 

 

4

-      Grade 3

 

 

 

4

 

 

 

4

Pigmentation, tubular, mf

0

0

3

10

0

0

7

10

-      Grade 1

 

 

3

4

 

 

7

1

-      Grade 2

 

 

 

6

 

 

 

8

-      Grade 4

 

 

 

 

 

 

 

1

Applicant's summary and conclusion

Conclusions:
Under the conditions of this Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test, the oral administration by gavage of the test substance to Wistar rats revealed treatment-related adverse systemic findings in parental animals (F0) manifested in the kidneys of both sexes at 1150 mg/kg bw/day.
Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity was 350 mg/kg bw/d in both sexes of parental animals. The no observed adverse effect level (NOAEL) for reproductive performance and fertility was 1150 mg/kg bw/day in both sexes of parental animals.
The NOAEL for developmental toxicity in the F1 progeny was 1150 mg/kg bw/day.
Executive summary:

The test substance was administered daily as a liquid preparation to groups of 10 male and 10 female Wistar rats (F0 animals) by gavage at nominal doses of 120, 350 and 1150 mg/kg bw/d. Control animals (10 male and 10 female Wistar rats) were dosed daily with the vehicle only (deionized water). The duration of treatment covered a 2 weeks premating period and mating period in both sexes (mating pairs were from the same dose group), approximately 3 days post-mating in males, the entire gestation period, up to 13 days of the lactation period in females as well as up to one day prior to the day of schedule sacrifice of all animals.

The parents' and the pups' state of health was checked each day, and parental animals were examined for their mating and reproductive performances. After 2 weeks of premating treatment the F0 animals were mated to produce F1 generation pups. Mating was discontinued as soon as sperm were detected in the vaginal smear. F0 animals were examined for their reproductive performance including determination of the number of implantation sites and the calculation of post-implantation loss for all F0 females. A detailed clinical observation (DCO) was performed in all animals before initial test substance administration and, as a rule, thereafter at weekly intervals. Water consumption of the F0 parents was determined once weekly over a period of 3 days during premating. In dams, water consumption was determined for GD 0 - 3, 7 - 10, 14 - 17 and PND 1 - 4, 4 - 7, 7 - 10, 10 - 13. Food consumption of the F0 parents was determined once weekly during premating. In dams, food consumption was determined for GD 0 - 7, 7 - 14, 14 - 20 and PND 1 - 4, 4 - 7, 7 - 10, 10 - 13. Body weights of F0 parents were determined once a week. During gestation and lactation period, F0 females were weighed on GD 0, 7, 14 and 20 and on postnatal days (PND) 0, 4, 7, 10 and 13. Estrous cycle data were evaluated for F0 generation females over a two-week period prior to mating until evidence of mating occurred. Moreover, the estrous stage of each female was determined on the day of scheduled sacrifice.

The pups were sexed and examined for macroscopically evident changes on PND 0. They were weighed on PND 1, 4, 7 and 13. Their viability was recorded. At necropsy on PND 4, as a result of standardization, the surplus pups were sacrificed under isoflurane anesthesia by decapitation. At necropsy on PND 13, one selected male and one female pup per litter was sacrificed under isoflurane anesthesia by decapitation, all other pups (on PND 13) were sacrificed with CO2, under isoflurane anesthesia. All pups were examined macroscopically for external and visceral findings. Anogenital distance (defined as the distance from the anus [center of the anal opening] to the base of the genital tubercle) measurements were conducted in a blind randomized fashion, using a measuring ocular on all live male and female pups on PND 1. All surviving male pups were examined for the presence or absence of nipple / areola anlagen on PND 13. The number of nipple / areola anlagen were counted. Blood samples were taken from all surplus pups at PND 4 as well as one male and one female pup per litter at PND 13 by decapitation under isoflurane anesthesia for determination of thyroid hormone concentrations. Clinico-chemical and hematological examinations were performed in 5 animals per sex and group towards the end of the administration period. Blood samples from all dams at PND 14 and all males at termination were taken by puncturing the retrobulbar venous plexus under isoflurane anesthesia for hormone measurement. At the end of the administration period a functional observational battery was performed, and motor activity was measured in 5 parental males and females per group. All F0 parental animals were sacrificed by decapitation, under isoflurane anesthesia, and were assessed by gross pathology. Weights of selected organs were recorded, and a histopathological examination was performed.

The various analyses confirmed the stability of the test substance in deionized water over a period of 7 days at room temperature and confirmed the overall accuracy of the prepared concentrations.

The following test substance-related adverse effects / findings were noted:

Test group 3: 1150 mg/kg bw/d (corresponding to 1003 mg/kg bw/d active ingredient)

F0 Parental Animals

Clinical examinations, reproductive performance, and clinical pathology

- No test substance-related adverse findings

Pathology

- Statistical significant kidney weight increase in males: absolute (+ 20.58 %) and relative (+ 21.49 %), and females: relative (+ 18.06 %)

- Degeneration-regeneration of tubules in kidneys: all males and 9 out of 10 females (minimal to moderate)

- Tubular pigmentation in kidneys of all males and females (minimal to slight)

F1 Pups

Clinical examinations / gross findings and clinical pathology

- No test substance-related adverse findings

Test group 2: 350 mg/kg bw/d (corresponding to 305 mg/kg bw/d active ingredient)

F0 Parental Animals

Clinical examinations, reproductive performance, clinical pathology, and pathology

- No test substance-related adverse findings

F1 Pups

Clinical examinations / gross findings and clinical pathology

- No test substance-related adverse findings

Test group 1: 120 mg/kg bw/d (corresponding to 105 mg/kg bw/d active ingredient)

F0 Parental Animals

Clinical examinations, reproductive performance, clinical pathology, and pathology

- No test substance-related adverse findings

F1 Pups

Clinical examinations / gross findings and clinical pathology

- No test substance-related adverse findings

Under the conditions of this Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test, the oral administration by gavage of the test substance to Wistar rats revealed treatment-related adverse systemic findings in parental animals (F0) manifested in the kidneys of both sexes at 1150 mg/kg bw/day (i.e. 1003 mg/kg bw/day active ingredient).

Thus, the no observed adverse effect level (NOAEL) for general systemic toxicity was 350 mg/kg bw/d (i.e. 305 mg/kg bw/d active ingredient) in both sexes of parental animals. The no observed adverse effect level (NOAEL) for reproductive performance and fertility was 1150 mg/kg bw/day (i.e. 1003 mg/kg bw/day active ingredient) in both sexes of parental animals.

The NOAEL for developmental toxicity in the F1 progeny was 1150 mg/kg bw/day (i.e. 1003 mg/kg bw/day active ingredient).