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EC number: 283-829-2 | CAS number: 84731-70-4
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
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- Endpoint summary
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- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Key value for chemical safety assessment
- Toxic effect type:
- dose-dependent
Effects on fertility
Description of key information
Two-generation reproductive toxicity test:
NOAEL was considered to be 1000 mg/kg/day (OECD 416).
Reproductive - developmental screening toxicity test:
NOEL for reproductive toxicity was considered to be 1000 mg/kg/day; NOAEL was considered to be greater than 1000 mg/kg/day. (OECD 422)
Link to relevant study records
- Endpoint:
- two-generation reproductive toxicity
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- From 2017-07-27 to 2018-08-06
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
- GLP compliance:
- yes (incl. QA statement)
- Limit test:
- no
- Specific details on test material used for the study:
- Batch No.: 20170214
Purity: >99% - Species:
- rat
- Strain:
- Sprague-Dawley
- Details on species / strain selection:
- Rat is the preferred species for reproduction toxicity study and is accredited in the OECD Guideline.
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Beijing Vital River Laboratory Animal Technology Co., Ltd.
- Age at study initiation: 35-41 days old (on arrival)
- Weight at study initiation: 112.80-138.55 for females and 122.29-162.59g for males (on arrival); 163.82-234.77g for males and 104.43-188.57g for females (on the final day of the acclimatization)
- Housing: plastic cages (L46.0×W31.5 ×H20.0cm) on cage racks (L170.0cm×W50.0cm×H160.0cm); two rats at most in per cage
- Diet: ad libitum. The sterilized SPF rodent growth and breeding feed were used in this test. All the nutrition components and contaminants were within the permitted limits described in the national standard.
- Water: ad libitum. Drinking water was purified with HT-R01000 purity system and routinely analyzed (at least annually), and all parameters were within the permitted limits described in the national standard.
- Acclimation period: eight days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.8-25.5 °C
- Humidity (%): 38-70%
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours dark - Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
As preparing the test item, calculate the theoretical weight and range of the test item according to the prepared volume and concentration shown below. Weigh the test item and place into a beaker. Add some solvent, mix and pour into a cylinder with lid. Wash the beaker with solvent and pour into the cylinder at least three times. Add solvent in the cylinder to the scale of prepared volume, mix and pour into a labeled bottle for use.
VEHICLE
- Justification for use and choice of vehicle (if other than water): The test item has good solubility in corn oil, and the corn oil has no adverse effects by gavage as 4 ml/kg.bw to rats according to the experience of this lab, at the same time, it is accredited vehicle in the Guideline, so corn oil was selected as vehicle in this study. - Details on mating procedure:
- - M/F ratio per cage: 1:1
- Length of cohabitation: two weeks
- Proof of pregnancy: The presence of vaginal plugs was considered as the evidence of successful copulation. The day on which vaginal plugs was detected was considered as GD0.
- The mated females were caged individually for the birth and rearing of their pups.
- In the second week of the mating period, females without successful copulation were replaced with another male animal from the same group (a male that already has successfully mated with another female.)
- After the mating period, females without successful copulation were caged individually until sacrifice (more than 21 days after the last day of the mating period), at the same time, females with successful copulation but turning out to be non-pregnant were killed for necropsy. - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The analytical check for the concentrations of prepared test item was conducted for four times, respectively at the early stage and the last preparation, and twice in the course of the test.
Preparation of the sample:
Three samples were prepared by adding 0.5 mL of 10 mg/L standard solution to 99.5 mL of the dilution water (total volume: 100 mL) to obtain 0.05 mg/L of test solutions, respectively. They were transferred into each 250 mL separatory funnel. 30 mL of dichloromethane was added and shaked for 5 minutes. The dichloromethane layer was passed through sodium sulphate to remove moisture and collected in a round flask. This procedure was repeated one more time. Dichloromethane was evaporated using rotary evaporator at 30~40℃. Final volume of sample was adjusted to 1 mL using acetone and then analyzed. The recovery efficiency was calculated and this should be in the range 80-120%.
Calculation method of concentration:
Concentrations of the test item were quantitated by an external standard method. The peak area response for this test item in each calibration standard chromatogram was measured and a calibration curve constructed by linear regression of standard area response versus standard concentration. The measured concentration of the test item was calculated from the calibration curve using GC Chemstation . All value was expressed after correction of concentration factor (100-200 fold concentration) in this report. - Duration of treatment / exposure:
- For F0-generation animals, the administration was continued during the premating period of at least 10 weeks, mating period of no longer than 2 weeks, gestation and lactation period (for females) until the weaning of their pups.
For F1-generation animals selected for mating, the administration was continued from PND22 to the weaning of their pups at the same doses with their mothers, including the premating period of at least 10 weeks, mating period of no longer than 2 weeks, gestation and lactation period (for females). The females in the process of parturition were not dosed. - Frequency of treatment:
- once daily in the morning
- Details on study schedule:
- After all litters of F0-generation were weaned, 28 female pups and 28 male pups were selected at random selection from as many litters as possible in each group to rear F1-generation.
- Dose / conc.:
- 0 mg/kg bw/day (nominal)
- Dose / conc.:
- 40 mg/kg bw/day (nominal)
- Dose / conc.:
- 200 mg/kg bw/day (nominal)
- Dose / conc.:
- 1 000 mg/kg bw/day (nominal)
- No. of animals per sex per dose:
- 28
- Control animals:
- yes, concurrent no treatment
- Details on study design:
- - Dose selection rationale:
In repeated dose 90-day oral toxicity study of the test substance in rats, no toxicologically significant effect was observed at the dose levels of 10, 100 and 1000mg/kg.d, and No Observed Adverse Effect Level (NOAEL) was considered to be 1000mg/kg.d.
Refer to the results in repeated dose 90-day oral toxicity study of DEHCH in rats supplied by sponsor, three dose levels were used in this study including 1000, 200 and 40mg/kg.d. A concurrent control group was included at the same time. - Parental animals: Observations and examinations:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily in the morning hours; All animals were observed for morbidity and mortality twice daily at the beginning and the end of work (once daily on non working day).
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once per week
BODY WEIGHT: Yes
- Time schedule for examinations: Once per week during the premating and mating period. Mated females were weighed on gestation day (GD) 0, 7, 14 and 21, and on day 0, 4, 7, 14 and 21 of lactation. All animals were weighed on their scheduled necropsy date.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
During the premating and gestation period, the ration food was added once weekly. The added food weight was 500±10 g per cage in the premating period and 200±10 g per cage in the gestation period. The food was weighed again one day (24 h± 1.5 h) later as surplus food weight. The results were expressed in g per animal per day.
OTHER
- Parturition observation: All pregnant females were observed for parturition from GD21 twice daily in the morning and afternoon respectively (once daily on non working day). Any difficulties and abnormalities occurring during parturition were recorded. - Oestrous cyclicity (parental animals):
- For F0-generation and selected F1-generation females, vaginal smears to evaluate the estrus cycle length and normality were made for two weeks prior to mating. For each female, vaginal smear was made daily and was observed under the microscope to evaluate their estrus cycle stage.
- Sperm parameters (parental animals):
- Parameters examined in male parental generations:
Testicular sperm count, Epididymal sperm morphology, Epididymal sperm motility and count - Litter observations:
- STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- Maximum of 8 pups with 4 males and 4 females per litter, and if the number of one sex was not enough, another sex was added. The rest pups were euthanized with CO2.
PARAMETERS EXAMINED
The following parameters were examined in [F1 / F2] offspring:
For pups in lactation period, a cage-side observation of the litters was conducted once daily in order to keep nest disturbance to a minimum, except for PND0, 4, 7, 14 and 21. On these days, pups were observed individually, and the number of live pups was recorded. On PND0, the number of each sex, stillbirth and grossly malformed pups was recorded and evaluated.
On PND0 and 4, litter weights were recorded. On PND4 after culling, and on PND7, 14 and 21, the pups were weighed individually. - Postmortem examinations (parental animals):
- SACRIFICE
- Male animals: Males were sacrificed after the end of the mating period, and dams were sacrificed after all litters were weaned.
- Maternal animals: Females without successful copulation and females with successful copulation but without delivery were sacrificed more than 21 days after the last day of the mating period.
GROSS NECROPSY
- The necropsy included carefully examinations of the external features of the carcass, external body orifices, the abdominal, thoracic, and cranial cavities and their contents of all animals, and any abnormal findings were recorded. For the parous females, the number of implantation sites in the uteri and the number of corpora lutea were recorded. For non-mated or non-pregnant females, the uteri were observed for the presence of implantation site.
HISTOPATHOLOGY / ORGAN WEIGHTS
- Histopathology: Histopathology was examined on the following organs: Reproductive organs of the parental animals in the control and high-dose groups, and all males that failed to become sire and females that were non-mated or non-pregnant in the low- and mid- dose groups; all gross lesions found in the parental animals.
- Organ weights: For the parental animals of F0-generation and F1-generation, that included adrenals, brain, pituitary, kidneys, liver, spleen, thyroid, epididymides, uterus with cervix, ovaries, testes, prostate including seminal vesicles with coagulating glands; for the pups selected for necropsy, that included brain, spleen and thymus.
The organs were weighed as soon as possible after dissection to avoid drying. The pituitary and thyroid were weighed after the fixation in 10% neutral-buffered formalin. Organ-to-body weight ratios were calculated. - Postmortem examinations (offspring):
- GROSS NECROPSY
One male and one female pup of each litter as possibly, and all pups with external abnormalities or clinical signs that had not recovered as necropsy were selected for necropsy. On the day of necropsy, the selected pups were euthanized by CO2 inhalation followed by exsanguinations from abdominal aorta and subjected to a full necropsy and general observation. The other live pups were humanely killed by CO2 euthanasia.
The stillborn pups or dead pups found on PND0~4, when not macerated, were observed for stomach contents (if containing milk) and external abnormality, and then were fixed in Bouin’s solution for examination of soft tissue. The dead pups found after PND5, when not macerated, were observed for external abnormality, and then were necropsied for any gross lesions and stomach contents (if containing milk).
HISTOPATHOLOGY / ORGAN WEIGTHS
- Histopathology: Histopathology was examined on the following organs: Reproductive organs of the parental animals in the control and high-dose groups, and all males that failed to become sire and females that were non-mated or non-pregnant in the low- and mid- dose groups; all gross lesions found in the parental animals.
- Organ weights: For F1-generation, that included adrenals, brain, pituitary, kidneys, liver, spleen, thyroid, epididymides, uterus with cervix, ovaries, testes, prostate including seminal vesicles with coagulating glands; for the pups selected for necropsy, that included brain, spleen and thymus.
The organs were weighed as soon as possible after dissection to avoid drying. The pituitary and thyroid were weighed after the fixation in 10% neutral-buffered formalin. Organ-to-body weight ratios were calculated. - Statistics:
- The resulting data were analyzed using the methods mentioned below. P﹤0.05 was considered as a level of significance.
a) The data of clinical signs were analyzed by Chi-square test;
b) Data of the mean body weight and mean body weight gain, food consumption were statistic analyzed by decision tree; data of the food efficiency of the parental animals during the premating period will be statistic analyzed by decision tree;
c) The precoital interval and the gestation length were evaluated by Mann-Whitney U-test for grade analysis, and were statistic analyzed by decision tree;
e) Estrus cyclicity was evaluated by Chi-square test for number of acyclic animals and number of animals with prolonged estrus period, and by decision tree for mean cycle length and number of whole estrus cycle during the exam period;
f) Sperm parameters were evaluated by decision tree for sperm count and motility parameters, and by Chi-square test for sperm morphology;
g) Incidences of pathological findings were analyzed by the unilateral Fisher’s exact probability test.
All data analysis was done with test software in this facility or SPSS 17.0.
For the data that have no difference between the control group and dose group, it was not necessary to perform the statistical analysis. - Reproductive indices:
- Female mating index = (number of mated females/number of females placed with males) ×100
Male mating index = (number of mated males/number of males placed with females) ×100
Male fertility index = (number of males siring a litter/number of males placed with females) ×100
Female fertility index = (number of pregnant females/number of females placed with males) ×100
Female fecundity index = (number of pregnant females/number of mated females) ×100
Gestation index = (number of females with live pups / number of pregnant females) ×100
Live birth index = (number of pups born alive / number of pups born) ×100
Viability index of lactation = (number of surviving pups on PND21 / number of pups after culling on PND4) ×100
Sex ratio = (number of live male pups on PND0/ number of live pups on PND0 ) ×100 - Offspring viability indices:
- Viability index of lactation = (number of surviving pups on PND21 / number of pups after culling on PND4) ×100
Sex ratio = (number of live male pups on PND0/ number of live pups on PND0 ) ×100 - Clinical signs:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For males, one animal in each dose group respectively was observed with dehairing on part of body during the premating and mating period, but that was not considered to be treatment-related clinical sign.
For females, dehairing, vaginal hemorrhage, soiled perineal region, scab around eye were observed on one or two animals in the different period, and two animals were observed with tumor, but the incidence of these signs had no significant increase in all dose groups compared with the control group, so that were not considered to be treatment-related clinical signs. - Mortality:
- mortality observed, non-treatment-related
- Description (incidence):
- Two females (No. 2015 and 2019) of the control group and one female (No. 2323) of the high-dose group were found dead on GD26, GD25 and GD23 respectively, at necropsy, embryos were found in their uterus, and no apparent cause of death was found. One male (No. 1300) of the high-dose group was found dead in the premating period, at necropsy, diaphragmatic hernia was found, that was considered as spontaneous death and without toxicological significance.
The mortality of male and female animals in the high-dose group had no significant increase compared with the control group, so that result was considered to be an incidental result without toxicological significance. - Body weight and weight changes:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males and females, no significant difference was observed on the mean bodyweight and body weight gain in all dose groups compared with the control group (p>0.05).
Mating period
For males, no significant difference was observed in all dose groups compared with the control group (p>0.05).
Gestation period
No significant difference was observed in all dose groups compared with the control group (p>0.05).
Lactation period
No significant difference on the mean body weight of the parental females was observed in all dose groups compared with the control group (p>0.05). The body weight change from PND0 to PND4 had a statistically significant decrease in the high-dose group compared with the control group (p<0.05), but it recovered in the remaining lactation period. No significant difference on the body weight change was observed in the low- and mid- dose groups compared with the control group (p>0.05). - Food consumption and compound intake (if feeding study):
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males, the mean food consumption in some test weeks had a statistically significant increase in one or more dose groups compared with the control group(p<0.05 or p<0.01), and in the 7th test week, the mean food consumption in the low-dose group had a statistically significant decrease(p<0.01), at the same time, the total food consumption in the premating period had a statistically significant increase in the high-dose group compared with the control group(p<0.01).
For females, the mean food consumption in some test weeks had a statistically significant increase in the mid- and/or high- dose groups compared with the control group(p<0.05 or p<0.01), and in the 5th test week, the mean food consumption in the low-dose group had a statistically significant decrease(p<0.05), at the same time, the total food consumption in the premating period had a statistically significant increase in the mid- and high- dose groups compared with the control group(p<0.05 or p<0.01).
Premating period
The mean food consumption of the pregnant females in the mid- and high- dose groups had a statistically significant increase in the last week compared with the control group (p<0.01).
Base on the results about the food consumption above, the animals had a tendency to eat more after the exposure of test item at the dose of 1000 and 200mg/kg.d, but at the same time, no adverse effect on the body weight in each dose group was observed, so these results were considered without toxicological significance. - Food efficiency:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males, the decrease of mean food efficiency was observed in the high-dose group in the second week (p<0.05), but the average food efficiency in the whole premating period had no statistically significant difference in all dose groups compared with the control group (p>0.05), these results were considered to be incidental without toxicological significance.
For females, the decrease of mean food efficiency was observed in the high-dose group in the second test week (p<0.05), in addition, the average food efficiency in the whole premating period had a statistically significant decrease in the mid-dose group, but that had no statistically significant change in the other two dose groups, these results were considered to be incidental without toxicological significance. - Organ weight findings including organ / body weight ratios:
- effects observed, non-treatment-related
- Histopathological findings: non-neoplastic:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Scheduled necropsies
No treatment-related changes were found in males and females of high-dose group.
Based on the macroscopic findings, all gross lesions were examined microscopically. Testis atrophy, epididymis atrophy and prostate inflammatory cell infiltrate in histopathology were observed in the lesions of testis small, epididymis small and prostate small; kidney mineralization was observed in the lesions of kidney malformation; uterus amyloidosis was observed in the lesions of uterus nodule. All these abnormalities were facultative and were not treatment-related.
In males of all dose groups that failed to become sire, several cases of prostate inflammatory cell infiltrate and prostate abscess, one case of testis and epididymis atrophy were observed. In females that were non-mated or non-pregnant, ovary follicular cyst, decreased number/absent corpora lutea and uterus squamous metaplasia etc. were observed in some animals. No significant difference on the incidence of these abnormalities was observed in all dose groups compared with the control group (p>0.05), so that was considered not to be treatment-related.
Intercurrent dead animals
In F0 generation, the microscopic examination was conducted in four intercurrent dead animals, ovary hyperemia was observed in rat 2323.No abnormality was observed in the other animals. - Reproductive function: oestrous cycle:
- effects observed, non-treatment-related
- Description (incidence and severity):
- No differences were observed on all estrus cyclicity parameters in each dose group compared with the control group (p>0.05).
- Reproductive function: sperm measures:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Epididymal sperm motility and count
A statistically significantly increase on the total count of epididymal sperm was observed (p<0.05) in high-dose group, but that was not considered to be an adverse effect on the males. No statistically significant difference on the total count of epididymal sperm was observed in the other two dose groups compared with the control group (p>0.05).
Statistically significantly increases on the average path velocity (VAP), amplitude of lateral head displacement (ALH) in the high-dose group were observed (p<0.05), but these results were not considered to be the adverse effect. No statistically significant difference on the other sperm motility parameters was observed in all dose groups compared with the control group (p>0.05).
One male in the low-dose group (No.: 1104) was examined for epididymal sperm motility and count, but the report from TOX IVOS Sperm Analyzer showed that all sperms examined were static, it was considered that was not the actual state of the animal, but was caused by operation error, so the data of this animal were excluded from the statistical analysis.
Epididymal sperm morphology
No significant effect on the epididymal sperm morphology was observed in the examined males of all dose groups.
Testicular sperm count
No statistically significant difference on the testicular sperm count was observed in all dose groups compared with the control group (p>0.05). - Reproductive performance:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Fertility
In each group, twenty-eight males (27 males in the high-dose group) and 28 females were put together as one to one ratio for mating, and the mating period lasted for two weeks. 23, 24, 20 and 24 males were found to mate with female, and 18, 20, 15 and 21 males became sire in the control, low-, mid- and high- dose groups, respectively. The mating index and fertility index of males had no statistically significant difference in all dose groups compared with the control group (p>0.05).
25, 27, 24 and 27 females were found to mate with male, and 22, 22, 18 and 25 females were pregnant in the control, low-, mid- and high- dose groups, respectively. The mating index, fertility index and fecundity index of females had no statistically significant difference in all dose groups compared with the control group (p>0.05).
No difference was observed on precoital interval in females of all dose groups compared with the control group (p>0.05).
Pregnancy and Delivery Data
20, 22, 18 and 24 pregnant females survived delivery to obtain a litter with liveborn pups in the control, low-, mid- and high- dose groups, respectively. Two females in the control group and one female in the high-dose group were dead during the delivery. The gestation index had no statistically significant difference in all dose groups compared with the control group (p>0.05).
No statistically significant difference was observed on gestation length in all dose groups compared with the control group (p>0.05). - Key result
- Dose descriptor:
- NOAEL
- Effect level:
- 1 000 mg/kg bw/day (nominal)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- food consumption and compound intake
- organ weights and organ / body weight ratios
- reproductive performance
- Key result
- Critical effects observed:
- no
- Clinical signs:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For males, one or two animals were observed with dehairing and scar, abdominal distension or emaciation in the control, low- and mid- dose groups, but that were not considered to be treatment-related clinical signs.
For females, dehairing, and soiled perineal region were observed on one or two animals in the different period, and one animal in the low-dose group was observed with tumor, but the incidence of these signs had no significant increase in all dose groups, so that were not considered to be treatment-related clinical signs. - Mortality / viability:
- mortality observed, non-treatment-related
- Description (incidence and severity):
- One female (No. 2723) of the high-dose group was found dead on GD17, at necropsy, embryos were found in its uterus, and no apparent cause of death was found. Two males (No. 1408 and 1424) of the control group and one male (No. 1706) of the high-dose group were found dead in the premating period, at necropsy, thymus enlargement was found in rat 1408, and no obvious abnormality was found in rat 1424 and 1706.
The mortality of male and female animals in the high-dose group had no significant increase compared with the control group, so that result was considered to be an incidental result without toxicological significance. - Body weight and weight changes:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males, no significant difference was observed on the mean bodyweight and body weight gain in all dose groups compared with the control group (p>0.05). For females, no significant difference was observed on the mean bodyweight in all dose groups compared with the control group (p>0.05). In the 5th, 7th, 10th and11th test weeks, the body weight gain in one or more dose groups had a statistically significant decrease or increase compared with the control group (p<0.05 or p<0.01), but the total body weight gain during the whole premating period in each dose group had no significant difference compared with the control group (p>0.05), so that was considered to be an incidental result without toxicological significance.
Mating period
For males, no significant difference was observed in all dose groups compared with the control group (p>0.05).
Gestation period
No significant difference was observed in all dose groups compared with the control group (p>0.05).
Lactation period
No significant difference on the mean body weight and body weight change of the parental females was observed in all dose groups compared with the control group (p>0.05). - Food consumption and compound intake (if feeding study):
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males, the mean food consumption from the 6th test week to the 10th test week in the mid- and high- dose groups, and in the 8th test week in the low-dose group had a statistically significant increase compared with the control group(p<0.05 or p<0.01), at the same time, the total food consumption in the premating period had a statistically significant increase in the mid- and high- dose groups compared with the control group(p<0.01), and had no statistically significant difference in the low-dose (p>0.05).
For females, the mean food consumption in some test weeks had a statistically significant increase in the mid- and/or high- dose groups compared with the control group(p<0.05 or p<0.01), but no statistically significant increase on the total food consumption in the premating period was observed in these groups compared with the control group(p>0.05).
Gestation period
No statistically significant difference on the mean food consumption of the pregnant females was observed during the gestation period in all dose groups compared with the control group (p>0.05).
Base on the results about the food consumption above, the animals had a tendency to eat more after the exposure of test item at the dose of 1000 and 200mg/kg.d, but at the same time, no adverse effect on the body weight in each dose group was observed, so these results were considered without toxicological significance. - Food efficiency:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Premating period
For males, the decrease of mean food efficiency was observed in the high-dose group from the 8th to the 11th test week (p<0.05 or p<0.01), and in the mid-dose group in the 8th and 11th test week (p<0.05 or p<0.01) compared with the control group, at the same time, the average food efficiency in the whole premating period had a statistically significant decrease in the high-dose group compared with the control group(p<0.01), and had no statistically significant change in the other two dose groups. These decreases of the food efficiency were considered to be related with the increase of the food consumption.
For females, an increase or decrease of mean food efficiency was observed in one or more test weeks in all dose groups (p<0.05 or p<0.01), but the average food efficiency in the whole premating period had no statistically significant difference compared with the control group (p>0.05), these results were considered to be incidental without toxicological significance. - Sexual maturation:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For the males of F1 generation, no statistically significant difference was observed on the day of achievement of preputial separation and the mean body weight on this day in all dose groups compared with the control group (p>0.05).
For the females of F1 generation, no statistically significant difference was observed on the day of achievement of vaginal opening and the mean body weight on this day in all dose groups compared with the control group (p>0.05). - Organ weight findings including organ / body weight ratios:
- effects observed, non-treatment-related
- Description (incidence and severity):
- The following statistically significant difference compared with the control group was observed on organ weight:
Both of the absolute and relative pituitary weights in males of the low-dose group were statistically significant decreased compared with the control group (p<0.05 or p<0.01). The absolute pituitary weights in females of the mid- and high- dose groups were statistically significantly increased (p<0.05 or p<0.01), at the same time, the relative pituitary weight in females of the mid-dose group was statistically significantly increased (p<0.05).
The absolute liver weights in males and females of all dose groups were comparable with the control group, but the relative liver weight in males of the low-dose group was statistically significantly increased (p<0.05).
Both of the absolute and relative thyroid weights in males of the high-dose group and in females of the mid-dose group were statistically significantly increased (p<0.01).
Both of the absolute and relative spleen weights in males of the mid-dose group were statistically significantly increased (p<0.05).
The absolute brain weights in females of the mid- and high- dose groups were statistically significantly increased (p<0.05), but their relative brain weights were comparable with the control group, this was considered to be of no toxicological relevance.
The organ weights of the other organs in males and females of all dose groups were comparable with the control group. - Gross pathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Scheduled necropsies
No treatment-related changes were found in males and females of all dose groups.
Intercurrent dead animals
One female (No. 2723) of the high-dose group was found dead on GD17, at necropsy, uterus enlargement with fetuses was observed; two males (No. 1408 and 1424) of the control group were found dead in the premating period, at necropsy, thymus enlargement was observed in rat 1408 and no obvious abnormality was observed in rat 1424; one male (No. 1706) of the high-dose group was found dead in the premating period, at necropsy, no obvious abnormality was observed because of autolyze. - Histopathological findings:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Scheduled necropsies
No treatment-related changes were found in males and females of high-dose group.
Based on the macroscopic findings, all gross lesions were examined microscopically. No abnormality in histopathology was observed in the lesions of testis small and epididymis small.
In males of all dose groups that failed to become sire, prostate inflammatory cell infiltrate was observed in a few animals. In females that were non-mated or non-pregnant, ovary follicular cyst, decreased number/absent corpora lutea and uterus squamous metaplasia etc. were observed in some animals. No significant difference on the incidence of these abnormalities was observed in all dose groups compared with the control group (p>0.05), so that was considered not to be treatment-related.
Intercurrent dead animals
In F1 generation, the microscopic examination was conducted in four intercurrent dead animals, thymus hyperemia was observed in rat 1408, and ovary pigment was observed in rat 2723. No abnormality was observed in the other animals. - Other effects:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Estrus Cyclicity
No differences were observed on all estrus cyclicity parameters in each dose group compared with the control group (p>0.05).
Fertility
26, 28, 28 and 27males in the control, low-, mid- and high- dose groups and 28females in each group were put together as one to one ratio for mating, and the mating period lasted for two weeks. 22, 24, 23 and 23males in each group were found to mate with female, and 19, 20, 21 and 17 males became sire in the control, low-, mid- and high- dose groups, respectively. The mating index and fertility index of males had no statistically significant difference in all dose groups compared with the control group (p>0.05).
27, 25, 25 and 24 females were found to mate with male, and 24, 21, 22 and 20 females were pregnant in the low-, mid- and high- dose groups, respectively. The mating index, fertility index and fecundity index of females had no statistically significant difference in all dose groups compared with the control group (p>0.05). No difference was observed on precoital interval in all dose groups compared with the control group (p>0.05).
Pregnancy and Delivery Data
24, 21, 22 and 19 pregnant females survived delivery to obtain a litter with liveborn pups in the control, low-, mid- and high- dose groups, respectively. One female in the high-dose group was dead during the delivery. The gestation index had no statistically significant difference in all dose groups compared with the control group (p>0.05).
The mean gestation length in the mid-dose group had a significant extension compared with the control group (p<0.05), but that was within the range expected for SD rats, so this result was considered as an incidental result without toxicological significance. No statistically significant difference was observed on gestation length in the other two dose groups compared with the control group (p>0.05).
Sperm Analysis
- Epididymal sperm motility and count:
No statistically significant difference on the total count of epididymal sperm was observed in all dose groups compared with the control group (p>0.05).
Statistically significant decreases on the VAP, straight line velocity (VSL), curvilinear velocity (VCL), area of sperm motility in the low-dose group, and VSL, VCL, area of sperm motility in the mid-dose group were observed (p<0.01 or p<0.05). No statistically significant difference on all sperm motility parameters was observed in the high-dose group compared with the control group (p>0.05). No similar results were observed in F0 generation, at the same time, all the results of these parameters were absence of a dose relation among the dose groups, so it was considered the decreases on several sperm motility parameters in the low- and mid- dose groups were not an adverse effect of the treatment of the test item.
- Epididymal sperm morphology:
No significant effect on the epididymal sperm morphology was observed in the examined males of all dose groups.
- Testicular sperm count:
No statistically significant difference on the testicular sperm count was observed in all dose groups compared with the control group (p>0.05). - Key result
- Dose descriptor:
- NOAEL
- Generation:
- F1
- Effect level:
- 1 000 mg/kg bw/day (nominal)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- food consumption and compound intake
- organ weights and organ / body weight ratios
- other: Reproductive and developmental toxicity
- Key result
- Critical effects observed:
- no
- Clinical signs:
- effects observed, non-treatment-related
- Description (incidence and severity):
- During the lactation period, one litter including eight pups in the control group were observed with hypothermia on PND2, and was missing later; one litter including six pups in the mid-dose group were observed with sparse fur from PND14 to PND18, and recovered later. No pup with any abnormality and sign was observed in the other groups. All signs observed were considered as an incidental result without toxicological significance.
- Body weight and weight changes:
- effects observed, non-treatment-related
- Description (incidence and severity):
- The mean body weights of live pups in all dose groups had no statistically significant difference during the lactation period compared with the control group (p>0.05).
- Organ weight findings including organ / body weight ratios:
- effects observed, non-treatment-related
- Description (incidence and severity):
- The absolute brain weights in female pups of all dose groups were statistically significantly increased (p<0.05 or p<0.01), but their relative brain weight was comparable with the control group, this was considered to be of no toxicological relevance.
- Key result
- Reproductive effects observed:
- no
- Conclusions:
- Under the conditions of the two-generation reproduction toxicity study in rats, the No Observed Adverse Effect Level (NOAEL) for parental toxicity to males and females, for exposure to the test substance by gavage, is considered to be 1000 mg/kg.d. The NOAEL for reproductive toxic effects to parental males and females, for exposure to the test item by gavage, is considered to be 1000 mg/kg.d. The NOAEL for developmental toxic effects to pups, after parental exposure to the test substance by gavage, is considered to be 1000 mg/kg.d.
- Executive summary:
A Two-generation reproduction toxicity study in rats was conducted on the test substance according to OECD Guideline 416.
In this study, twenty-eight rats/sex/group were exposed by gavage to 0, 40, 200 and 1000 mg/kg.d the test substance respectively. In F0 generation, males and females were exposed to the test item for at least ten weeks prior to mating, no longer than two weeks of the mating period; after that, males were killed for sperm analysis and necropsy, and females were exposed continuously during the gestation and lactation period until all pups were weaned. 28 rats/sex/group were selected from these pups as F1 generation. In F1 generation, males and females were exposed to the test item at the same doses with their parents from PND22, including the premating period of at least 10 weeks, mating period of at most 2 weeks, gestation and lactation period (for females), the males were killed for sperm analysis and necropsy after mating period, and the females were killed for necropsy after all pups were weaned. In two generations, one male and one female pup of each litter as possibly were selected for necropsy.
During the test, no treatment-related clinical signs and death of the parental animals in two generations was found at any dose level.
In two generations, no significant adverse effect on the body weight of parental males and females was observed during each period. At the same time, based on the results about the food consumption, the animals had a tendency to eat more after the exposure of test item at the dose of 1000 and 200mg/kg.d, but these results were considered without toxicological significance.
For the parental animals of two generations, no treatment-related effect was observed on all reproductive parameters, including the mating index, fertility index of males and females, pregnancy and delivery results and litter related results, etc. Additionally, estrus cyclicity and sperm parameters were not adversely affected by exposure to the test item in both generations.
For the pups of two generations, no treatment-related effect was observed on all developmental parameters, including the live birth index and the viability index of lactation, the mean number and body weight of live pups during lactation period. Additionally, no treatment-related clinical signs and abnormalities were observed in all pups. For the male and female pups of F0 generation selected for mating, the sexual maturation was not adversely affected in all dose groups.
At the necropsy of all parental animals and pups, no treatment-related gross change was observed; in microscopic examination, no toxicologically relevant change was observed in the reproductive organs of the examined parental animals. At the same time, no treatment-related effect was observed on the absolute and relative organ weights of all parental animals and pups selected for necropsy.
Under the conditions of the two-generation reproduction toxicity study in rats, the No Observed Adverse Effect Level (NOAEL) for parental toxicity to males and females, for exposure to the test item by gavage, is considered to be 1000 mg/kg.d. The NOAEL for reproductive toxic effects to parental males and females, for exposure to the test item by gavage, is considered to be 1000 mg/kg.d. The NOAEL for developmental toxic effects to pups, after parental exposure to the test item by gavage, is considered to be 1000 mg/kg.d.
- Endpoint:
- screening for reproductive / developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Study period:
- 2010-05-21 to 2010-10-06
- 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)
- GLP compliance:
- yes
- Limit test:
- no
- Specific details on test material used for the study:
- Batch No.: 20091203
Purity: 99.42% - Species:
- rat
- Strain:
- Wistar
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Harlan Laboratories Ltd, Blackthorn, Bicester, Oxfordshire, United Kingdom
- Age at study initiation: Approx. 12 wks
- Weight at study initiation: Males 322 g - 381 g; females 190 g - 236g.
- Housing:
-- Initially, all animals housed in groups of 5 in solid floor polypropylene cages with stainles steel mesh lids and softwood flake bedding
-- During mating stage, all animals were transferred to polypropylene grid floor cages suspended over trays lined with absorbant paper on a 1 male: 1 female basis within each dose group.
-- After mating, males were returned to initial housing.
-- Mated females were housed individually during gestation and lactation in solid floor polypropylene cages with stainless steeel mesh lids and softwood flakes.
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: 7 d
ENVIRONMENTAL CONDITIONS
- Temperature: 21 °C ± 2 °C
- Humidity: 55 % ± 15 %
- Air changes: ≥ 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light
IN-LIFE DATES: From: 25th May 2010 To: 9th July 2010 - Route of administration:
- oral: gavage
- Vehicle:
- arachis oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
The test item was prepared at the appropriate concentrations as a solution in Arachis oil BP. The stability and homogeneity of the test item formulations were previously determined. Results from the previous study showed the formulations to be stable for at least 21 days. Formulations were
therefore prepared weekly for the first two weeks and then twice monthly thereafter and stored at approximately 4 °C in the dark. - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The results indicate that the prepared formulations were within acceptable ranges for the purpose of the study.
- Duration of treatment / exposure:
- Up to 8 weeks
- Frequency of treatment:
- Daily
- Dose / conc.:
- 100 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 300 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 1 000 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- 10 animals per sex per dose
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: Based on 14 d range-finding study
- Rationale for animal assignment: Randomisation based on stratified body weights - Parental animals: Observations and examinations:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: All animals were examined for overt signs of toxicity, ill-health and behavioural change immediately before dosing, up to 30 min after dosing and 1 and 5 h after dosing during the working week. Animals were observed immediately before dosing, soon after dosing and one hour after dosing at weekends and public holidays except for females during parturition where applicable. All observations were recorded.
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals were examined for overt signs of toxicity, ill-health and behavioural change immediately before dosing, up to 30 min after dosing and 1 and 5 h after dosing during the working week. Animals were observed immediately before dosing, soon after dosing and one hour after dosing at weekends and public holidays except for females during parturition where applicable. All observations were recorded.
BODY WEIGHT
- Time schedule for examinations:
-- Males: Day 1 (prior to dosing), weekly until termination
-- Females: Day 1 (prior to dosing), weekly for females until mating was evident, days 0, 7, 14, 20 post coitum, days 1 and 4 post partum.
FOOD CONSUMPTION AND COMPOUND INTAKE:
During the maturation period, weekly food consumption was recorded for each cage of adults. This was continued for males after the mating phase. For females showing signs of mating, food consumption was recorded for the periods covering post coitum Days 0-7, 7-14 and 14-20. For females with live litters, food consumption was recorded of Days 1 and 4 post partum.
FOOD EFFICIENCY
- Body weight gain in kg/food consumption in kg per unit time × 100 calculated as time-weighted averages from the consumption and body weight gain data:
-- Males: Throughout the study period, except for mating phase
-- Females: During pre-mating stage.
Due to offspring growth and milk production, food efficiency could not be accurately calculated during gestation and lactation.
WATER CONSUMPTION
- Water consumption was measured throughout the study, with the exception of mating phase - Litter observations:
- On completion of parturition (Day 0 post partum) the number of live and dead offspring was recorded. Offspring were individually identified within each litter by tattoo on Day 1 post partum.
For each litter, the following was recorded:
Number of offspring born
Number of offspring alive recorded daily and reported on Days 1 and 4 post partum
Sex of offspring of Days 1 and 4 post partum
Clinical condition of offspring from birth to Day 5 post partum
Individual offspring weights on Days 1 and 4 post partum (litter weights were calculated retrospectively from this data). - Statistics:
- Data were processed to give group mean values and standard deviations where appropriate.
For body weights and food consumptions during gestation, group mean values were calculated using data from females which were observed to give birth to offspring.
For body weights and food consumptions during lactation, group mean values were calculated using data from females with live young at Day 5 of lactation. - Clinical signs:
- effects observed, non-treatment-related
- Description (incidence and severity):
- - No clinical signs of toxicity were detected.
- Episodes of increased salivation were evident in animals of either sex treated with 1000 mg/kg bw/d, together with incidences of noisy respiration evident in 2 males treated with 1000 mg/kg bw/d and 100 mg/kg bw/d. One male treated with 300 mg/kg bw/d also showed an isolated incident of red/brown staining around the mouth. Observations of this nature are commonly observed following the oral administration of unpalatable or slightly irritant test formulation, and in the absence of any associated changes are considered not to be of toxicological importance. Generalised fur scab loss formation and an open wound were evident in 1 female treated with 1000 mg/kg bw/d. 2 females treated with 100 mg/kg bw/d showed scab formation with one of these females also showing generalised fur loss. Observations of this nature are commonly observed in group house animals or during the lactation phase for parental females, and are considered not to be related to treatment. One male treated with 100 mg/kg bw/d had corneal opacity of the eyes between days 28 and 42. In the
absence of a true dose related response this finding was considered not to be of toxicological importance.
- One control female had episodes of fur loss between days 24 and 41. One control male had noisy respiration between days 19 and 42, and a further control male had increase salivation on day 38. In the absence of treatment, these were considered to be low incidence findings occasionally observed in laboratory maintained rats. - Mortality:
- no mortality observed
- Description (incidence):
- There were no unscheduled deaths during the treatment period.
- Body weight and weight changes:
- no effects observed
- Description (incidence and severity):
- - No adverse effects on body weight change were detected for treated males throughout the treatment period, or for females treated at all dose levels during the pre-mating, gestation or lactation phases of the study when compared to controls.
- Statistical analysis of the data did not reveal any significant intergroup differences. - Food efficiency:
- no effects observed
- Description (incidence and severity):
- Food efficiency was not affected for males throughout the treatment period, or for females during the pre-mating phase.
- Water consumption and compound intake (if drinking water study):
- effects observed, non-treatment-related
- Description (incidence and severity):
- Males from all treatment groups showed an increase in overall water consumption when compared to values from the male control group.
- Reproductive performance:
- no effects observed
- Description (incidence and severity):
- MATING:
No treatment-related effects were detected in mating performance. All paired animals mated within the first four days of pairing. Statistical analysis of pre-coital interval data did not reveal any significant intergroup differences.
FERTILITY:
No treatment-related effects were detected on fertility for treated animals when compared to controls.
One female treated with 1000 mg/kg/day did not achieve pregnancy following evidence of mating. In absence if any histopathological correlates in the reproductive organs to elucidate the cause of the non-pregnancy in either the paired female or male partner which did not produce a pregnancy, the intergroup difference was considered to be incidental and of no toxicological importance.
GESTATION LENGTH:
No treatment-related effects were detected in the length of gestation for treated females when compared to controls. All animals showed gestation lengths between 22 to 23.5 days. Statistical analysis of the data did not reveal any significant intergroup differences. - Dose descriptor:
- NOEL
- Effect level:
- 100 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: systemic toxicity
- Dose descriptor:
- NOAEL
- Effect level:
- 300 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- female
- Basis for effect level:
- other: systemic toxicity
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- 1 000 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: reproductive toxicity
- Clinical signs:
- no effects observed
- Description (incidence and severity):
- No obvious clinical signs of toxicity were detected for offspring from treated females when compared to controls. The incidental clinical signs detected throughout the control and treated groups, consisting on small size, offspring found dead or missing, no milk in stomach, cold, scab formation and physical injury were considered to be low incidence findings observed in offspring in studies of this type and were unrelated to test item toxicity.
- Mortality / viability:
- no mortality observed
- Description (incidence and severity):
- No significant differences were detected for corpora lutea and implantation counts for treated animals when compared to controls. Litter sizes and viability for treated groups were also comparable to controls. There were no intergroup differences in sex ratio (percentage male offspring) for litters from treated groups compared to control. Statistical analysis of the data did not reveal any significant intergroup differences.
- Body weight and weight changes:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There were no toxicologically significant differences in litter weights or mean offspring body weights between control and treated animals.
Litters from females treated with 1000 mg/kg/day had statistically significant increase in litter weight at Day 4 of lactation. In the absence of any effects in litter size or offspring weights the minimal (P<0.05) intergroup difference was considered to be of no toxicological significance. - Key result
- Dose descriptor:
- NOEL
- Generation:
- F1
- Effect level:
- 1 000 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: developmental toxicity
- Key result
- Critical effects observed:
- no
- Key result
- Reproductive effects observed:
- no
- Conclusions:
- The oral administration of the test substance to rats by gavage, at dose levels of 100, 300 and 1000 mg/kg/day, resulted in treatment-related effects in animals of either sex treated with 1000 and 300 mg/kg/day. No such effects were detected in animals of either sex treated with 100 mg/kg/day, hence the NOEL for systemic toxicity was considered to be 100 mg/kg/day.
The effects detected in the liver of females treated with 300 mg/kg/day was considered to be adaptive in nature and not to represent an adverse effect of treatment. As such the NOAEL for females was considered to be 300 mg/kg/day.
No treatment-related effects were observed for reproduction, therefore a NOEL for reproductive toxicity was considered to be 1000 mg/kg/day. The NOAEL was considered to be greater than 1000 mg/kg/day.
Referenceopen allclose all
All pregnant females with successful delivery obtained a litter with at least one liveborn pups, and 2, 0, 1 and 2 females delivered a litter with stillborn pup in the control, low-, mid- and high- dose groups, respectively. One female in the control group (No. 2016) and one female in the mid-dose group (No. 2216) had complete litter loss during the lactation period.
No statistically significant difference was observed on the mean number of corpora lutea and implantation sites in all dose groups compared with the control group (p>0.05). No difference was observed on the mean number of pups delivered and liveborn in all dose groups (p>0.05). No statistically significant difference was observed on the pre-implantation loss in all dose groups compared with the control group (p>0.05); the post-implantation loss in high-dose group had a significant decreased compared with the control group (p<0.01), but no toxicological significance; no statistically significant difference was observed on the post-implantation loss in low- and mid-dose groups compared with the control group (p>0.05).
Pup Data
- Pup status: There were 10, 0, 1 and 3stillborn pups in the control group and low-, mid-, high- dose groups, respectively. The live birth indexes in the low- and mid- dose groups were increased significantly compared with the control group (p<0.05 or p<0.01), but no significant adverse effect on the live birth index was observed in all dose groups. No pup in all groups was dead in the lactation period; and the viability index of lactation was 100% in each group.
- Mean number of pups: The mean number of live pups on PND0 had no statistically significant difference in all dose groups compared with the control group (p>0.05). The sex ratio of the live pups at birth had a statistically significant difference between the low-dose group and the control group (p<0.05), and more male pups were observed in the low-dose group, but no statistically significant difference on the sex ratio was observed in the mid- and high- dose groups (p>0.05), so that was considered to be an incidental result without toxicological significance. The mean number of live pups on the other time of the lactation period, including PND4, PND7, PND14 and PND21 had no statistically significant difference in all dose groups compared with the control group(p>0.05).
No statistically significant difference on the number of dead pups during the lactation period was observed in all dose groups (p>0.05).
- Pup clinical observations: During the lactation period, one litter including eight pups in the low-dose group were observed with sparse fur from PND13 to PND17, and recovered later. One pup in the litter of 2112 was observed with walking difficulty from PND19, and did not recover until being killed as scheduled. No pup with any abnormality and sign was observed in the other groups. The number of pups with signs in the low-dose group had statistically significant increase compared with the control group (p<0.01), but this was considered as an incidental result without toxicological significance.
- Pup body weights: The mean body weights of live pups in all dose groups had no statistically significant difference during the lactation period compared with the control group (p>0.05).
- Organ Weight of Pups
No statistically significant difference on absolute and relative organ weight was observed in all dose groups compared with the control group (p>0.05).
- Macroscopic Observations of Pups
Stillborn and dead pups: No abnormalities were observed in stillborn and dead pups.
Scheduled necropsies: No abnormality was observed in pups selected for necropsy of all dose groups.
All pregnant females with successful delivery obtained a litter with at least one liveborn pups, two females in the control group and one female in the mid-dose group delivered a litter with stillborn pup. One female in the control group (No. 2402) and one female in the high-dose group (No. 2721) had complete litter loss during the lactation period.
No statistically significant difference was observed on the mean number of corpora lutea and implantation sites in all dose groups compared with the control group (p>0.05). No difference was observed on the mean number of pups delivered and liveborn in all dose groups (p>0.05). The pre-implantation loss had a statistically significant decrease (p<0.05 or p<0.01) in the mid- and high- dose groups, but without toxicological significance. No statistically significant difference was observed in the low-dose group (p>0.05). No statistically significant effect on the post-implantation loss was observed in all dose groups (p>0.05).
Pup Data
- Pup status: There were 2, 0, 1 and 0 stillborn pups in the control group and low-, mid-, high- dose groups, respectively. No statistically significant effects on the live birth index was observed in all dose groups (p>0.05).1, 3, 2 and 0 pups respectively in the control, low-, mid- and high- dose groups were dead in the lactation period. No statistically significant effect on the viability index of lactation was observed in all dose groups (p>0.05).
- Mean number of pups: The mean number of live pups on PND0 had no statistically significant difference in all dose groups compared with the control group(p>0.05), at the same time, no statistically significant difference on the sex ratio at birth was observed in all dose groups(p>0.05). The mean number of live pups on the other time of the lactation period, including PND4, PND7, PND14 and PND21 had no statistically significant difference in all dose groups compared with the control group(p>0.05). No statistically significant difference on the number of dead pups during the lactation period was observed in all dose groups (p>0.05).
- Pup clinical observations: During the lactation period, one litter including eight pups in the control group were observed with hypothermia on PND2, and was missing later; one litter including six pups in the mid-dose group were observed with sparse fur from PND14 to PND18, and recovered later. No pup with any abnormality and sign was observed in the other groups. All signs observed were considered as an incidental result without toxicological significance.
- Pup body weights: The mean body weights of live pups in all dose groups had no statistically significant difference during the lactation period compared with the control group (p>0.05).
- Organ Weight of Pups: The absolute brain weights in female pups of all dose groups were statistically significantly increased (p<0.05 or p<0.01), but their relative brain weight was comparable with the control group, this was considered to be of no toxicological relevance.
- Macroscopic Observations of Pups
Stillborn and dead pups: No abnormalities were observed in stillborn and dead pups.
Scheduled necropsies: No abnormality was observed in pups selected for necropsy of all dose groups.
- Stillborn and dead pups: No abnormalities were observed in stillborn and dead pups.
- Scheduled necropsies: No abnormality was observed in pups selected for necropsy of all dose groups.
Result tables are provided in "Statistic data table" attached to the section of Attached background material below.
Individual data are provided in "Individual data appendix" attached to the section of Attached background material below.
Pathology detail results are provided in "Pathology Report" attached to the section of Attached background material below.
Effect on fertility: via oral route
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEL
- 1 000 mg/kg bw/day
- Study duration:
- subchronic
- Species:
- rat
- Quality of whole database:
- Guideline study, GLP study
Effect on fertility: via inhalation route
- Endpoint conclusion:
- no study available
Effect on fertility: via dermal route
- Endpoint conclusion:
- no study available
Additional information
Reproductive - developmental screening toxicity test:
A reproductive-developmental screening study is available. The oral administration of the test substance to rats by gavage, at dose levels of 100, 300 and 1000 mg/kg/day, resulted in treatment-related effects in animals of either sex treated with 1000 and 300 mg/kg/day. No such effects were detected in animals of either sex treated with 100 mg/kg/day, hence the NOEL for systemic toxicity was considered to be 100 mg/kg/day.
The effects detected in the liver of females treated with 300 mg/kg/day was considered to be adaptive in nature and not to represent an adverse effect of treatment. As such the NOAEL for females was considered to be 300 mg/kg/day. No treatment-related effects were observed for reproduction, therefore a NOEL for reproductive toxicity was considered to be 1000 mg/kg/day. The NOAEL was considered to be greater than 1000 mg/kg/day.
Two-generation reproductive toxicity test:
A Two-generation reproduction toxicity study in rats was conducted on the test substance according to OECD Guideline 416.
In this study, twenty-eight rats/sex/group were exposed by gavage to 0, 40, 200 and 1000 mg/kg.d the test substance respectively. In F0 generation, males and females were exposed to the test item for at least ten weeks prior to mating, no longer than two weeks of the mating period; after that, males were killed for sperm analysis and necropsy, and females were exposed continuously during the gestation and lactation period until all pups were weaned. 28 rats/sex/group were selected from these pups as F1 generation. In F1 generation, males and females were exposed to the test item at the same doses with their parents from PND22, including the premating period of at least 10 weeks, mating period of at most 2 weeks, gestation and lactation period (for females), the males were killed for sperm analysis and necropsy after mating period, and the females were killed for necropsy after all pups were weaned. In two generations, one male and one female pup of each litter as possibly were selected for necropsy.
During the test, no treatment-related clinical signs and death of the parental animals in two generations was found at any dose level.
In two generations, no significant adverse effect on the body weight of parental males and females was observed during each period. At the same time, based on the results about the food consumption, the animals had a tendency to eat more after the exposure of test item at the dose of 1000 and 200mg/kg.d, but these results were considered without toxicological significance.
For the parental animals of two generations, no treatment-related effect was observed on all reproductive parameters, including the mating index, fertility index of males and females, pregnancy and delivery results and litter related results, etc. Additionally, estrus cyclicity and sperm parameters were not adversely affected by exposure to the test item in both generations.
For the pups of two generations, no treatment-related effect was observed on all developmental parameters, including the live birth index and the viability index of lactation, the mean number and body weight of live pups during lactation period. Additionally, no treatment-related clinical signs and abnormalities were observed in all pups. For the male and female pups of F0 generation selected for mating, the sexual maturation was not adversely affected in all dose groups.
At the necropsy of all parental animals and pups, no treatment-related gross change was observed; in microscopic examination, no toxicologically relevant change was observed in the reproductive organs of the examined parental animals. At the same time, no treatment-related effect was observed on the absolute and relative organ weights of all parental animals and pups selected for necropsy.
Under the conditions of the two-generation reproduction toxicity study in rats, the No Observed Adverse Effect Level (NOAEL) for parental toxicity to males and females, for exposure to the test item by gavage, is considered to be 1000 mg/kg.d. The NOAEL for reproductive toxic effects to parental males and females, for exposure to the test item by gavage, is considered to be 1000 mg/kg.d. The NOAEL for developmental toxic effects to pups, after parental exposure to the test item by gavage, is considered to be 1000 mg/kg.d.
Effects on developmental toxicity
Description of key information
Pre-natal developmental study in rats:
NOEL for reproductive and developmental toxicity was considered to be 1000 mg/kg bw/day; NOAEL was considered to be greater than 1000 mg/kg bw/day. (OECD 414)
Pre-natal developmental study in rabbits:
The maternal and developmental No observed Adverse Effect Level (NOAEL) for test item was established as being at least 1000 mg/kg/day. (OECD 414)
Link to relevant study records
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- From 2012-02-19 to 2012-03-08
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 414 (Prenatal Developmental Toxicity Study)
- Qualifier:
- according to guideline
- Guideline:
- EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)
- Qualifier:
- according to guideline
- Guideline:
- EU Method B.31 (Prenatal Developmental Toxicity Study)
- Qualifier:
- according to guideline
- Guideline:
- other: Japanese Ministry of Agriculture, Forestry and Fisheries Testing Guidelines for Toxicology Studies 12 NohSan No. 8147 (2000-11-24)
- GLP compliance:
- yes (incl. QA statement)
- Limit test:
- yes
- Specific details on test material used for the study:
- Batch No.: 20111009
Purity: 99.29% - Species:
- rat
- Strain:
- Sprague-Dawley
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River (UK), Margate, Kent, United Kingdom
- Age at study initiation: Approx. 10-12 wks
- Weight at study initiation: 194 g to 303 g
- Fasting period before study:
- Housing: Individually in solid floor polypropylene cages with stainless steel lids furnished with softwood flakes
- Diet: Pelletted diet ad libitum
- Water: Mains drinking water ad libitum
- Acclimation period:
ENVIRONMENTAL CONDITIONS
- Temperature: Targeted to 21 °C ± 2 °C
- Humidity: Targeted to 55 % ± 15 %
- Air changes: ≥ 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light - Route of administration:
- oral: gavage
- Vehicle:
- arachis oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
The test item was prepared at the appropriate concentrations as a solution in Arachis oil. - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- Non-GLP study; see attached supporting information
- Details on mating procedure:
- Time-mated, no further details provided. The day that positive evidence of mating was observed was designated as Day 0 of gestation.
- Duration of treatment / exposure:
- From day 5 to day 19 of gestation.
- Frequency of treatment:
- Daily
- Duration of test:
- Animals killed on day 20.
- Dose / conc.:
- 100 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 300 mg/kg bw/day (actual dose received)
- Dose / conc.:
- 1 000 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- 24 Females per dose (0 males)
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: Based on previous toxicity data
- Rationale for animal assignment: Randomised based on stratified body weights. - Maternal examinations:
- DETAILED CLINICAL OBSERVATIONS:
- Time schedule: Gestation period - daily. Dosing period - immediately before dosing, soon after dosing, 1 hr post dosing. Additional observation 5 hr post dosing during working week.
BODY WEIGHT:
- Time schedule for examinations: Day 3 (before start of treament), days 5, 6, 7, 8, 11, 14, 17, 20.
FOOD CONSUMPTION:
- Time schedule for examinations: Day 3 (before start of treament), days 5, 6, 7, 8, 11, 14, 17, 20.
WATER CONSUMPTION
- Time schedule for examinations: Recorded per animal for consecutive 3 d periods.
POST-MORTEM EXAMINATIONS:
- Sacrifice on gestation day 20
- Organs examined: Ovaries and uteri - Ovaries and uterine content:
- - Parameters examined: Corpera lutea, number position and type of intrauterine implantation, foetal sex, external foetal appearance, foetal weight, placental weight, gravid uterus weight
- Implantation types divided into categories as follows: (1) early death ( no visible distinction between placental/decidual tissue and embryonic tissue); (2) late death (separate embryonic/foetal and placental tissue visible); (3) dead foetus (died shortly before necropsy; included as late deaths for reporting purposes) - Fetal examinations:
- The foeti were killed by subcutaneous injection of sodium pentobarbitone. Foeti from each litter were divided into 2 groups and examined for skeletal alterations and soft tissue alterations. Alternative foeti were identified using an indelible marker and placed in Bouin's fixative. Foeti were transferred to a 90 % industrial methylated spirits (IMS) in distilled water and examined for visceral abnormalities under a low power binocular microscope. The remaining foeti were eviscerated, processed and the skeletons stained with alizqarin red. The foeti were examined for skeletal development and abnormalities. Following examination foeti that were examined for skeletal development were placed in 100 % gylcerol.
- Statistics:
- - Female body weight change, food consumption and gravid uterus weight: Bartlett's test for homogeneity of variance and 1-way analysis of variance followed by Dunnett's multiple comparison test or, if unequal variances observed, on alternative multiple comparison test
- All caesarean necropsy parameters and foetal parameters: Kruskal-Wallis non-parametric analysis of variance and a subsequent pairwise analysis of control values against treated values using the Mann-Whitney U test where significance was seen.
- Foetal evaluation parameters, including skeletal or visceral findings: Kruskal-Wallis non-parametric analysis of variance and Mann-Whitney U test. - Indices:
- - Pre and post-implantation loss.
- Sex ratio. - Clinical signs:
- no effects observed
- Description (incidence and severity):
- No clinically observed signs of toxicity were detected in animals throughout the study period.
- Mortality:
- no mortality observed
- Body weight and weight changes:
- effects observed, non-treatment-related
- Description (incidence and severity):
- - No toxicologically significant effects on body weight development were detected.
- Females treated with 1000 mg/kg bw/d and 300 mg/kg bw/d showed a statistically significant increase in body weights between days 6-7. Females treated with 300 mg/kg bw/d continued to show an increase in body weight gain between days 8-11 and 14-20. Subsequent cumulative body weight gain in females treated with 300 mg/kg bw/d was increased from day 11 onwards when compared to controls. Females from this treatment group also showed a statistically significant increase in body weight on day 20 and in gravid uterus weight. Increases in these parameters were not considered to represent an adverse effect of treatment and in the absence of true dose-related responses, the intergroup differences were considered not to be of toxicological significance. - Food consumption and compound intake (if feeding study):
- effects observed, non-treatment-related
- Description (incidence and severity):
- - No toxicologically significant effects on dietary intake were detected.
- Females treated with 300 mg/kg bw/d showed a statistically significant increase in food consumption from day 5 onwards. Females treated with 1000 mg/kg bw/d also showed a statistically significant increase in food consumption between days 14 and 17. An increase in the parameter was not considered to represent an adverse effect of treatment and in the absence of a true dose-related response the, the intergroup difference was considered not to be of toxicological significance. - Water consumption and compound intake (if drinking water study):
- no effects observed
- Description (incidence and severity):
- - No adverse effect on water consumption was detected.
- Statistical analysis did not reveal any significant differences. - Organ weight findings including organ / body weight ratios:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Animals treated with 300 mg/kg bw/d showed a statistically significant increase gravid uterus weight when compared to control animals. An increase in this parameter was not considered to represent an adverse effect of treatment and in the absence of a true dose-related response the intergroup difference was considered not to be of toxicological significance.
- Gross pathological findings:
- no effects observed
- Description (incidence and severity):
- No treatment-related macroscopic findings were dected in treated females.
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- 1 000 mg/kg bw/day
- Based on:
- test mat.
- Basis for effect level:
- other: maternal developmental toxicity
- Reduction in number of live offspring:
- no effects observed
- Description (incidence and severity):
- There was no adverse effect on in utero offspring survival, as assessed by the mean numbers of early or late resorptions, live litter size and implantation loss.
- Changes in litter size and weights:
- no effects observed
- Description (incidence and severity):
- There was no adverse effect on in utero offspring survival, as assessed by the mean numbers of early or late resorptions, live litter size and implantation loss.
- External malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.
- Skeletal malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.
- Visceral malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- For all dose groups there were no significant treatment-related trends in the proportion of foeti or litters with evidence of visceral or skeletal abnormalities. The type of visceral and skeletal abnormalities seen were those commonly observed in this type of study.
- Key result
- Dose descriptor:
- NOEL
- Effect level:
- 1 000 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- other: developmental toxicity
- Key result
- Developmental effects observed:
- not specified
- Conclusions:
- The oral administration of the test substance to pregnant rats was performed according to OECD Guideline 414. Rats dosed by oral gavage during organogenesis at dose levels of 100, 300 and 1000 mg/kg bw/day did not result in any toxicologically significant effects at any dose level. The NOEL was therefore considered to be 1000 mg/kg bw/day. No toxicolofically significant changes were detecetd in the offspring parameters measured. The NOEL for reproductive and developmental toxicity was therefore considered to be 1000 mg/kg bw/day. The NOAEL was considered to be greater than 1000 mg/kg bw/day.
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- From 2019-10-30 to 2020-05-07
- 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:
- 2018
- Deviations:
- no
- GLP compliance:
- yes
- Limit test:
- no
- Specific details on test material used for the study:
- Batch No.: 20190107_1
Purity: 98.6% - Species:
- rabbit
- Strain:
- New Zealand White
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River (Chatillon sur Chalaronne, France).
- Age at study initiation: 18-20 weeks
- Weight at study initiation: between 3038 and 4277 g
- Fasting period before study: Not fasted
- Housing: housed individually in cages with perforated floors (Ebeco, Germany, dimensions 67 x 62 x 55 cm) equipped with water bottles
- Diet: Pelleted diet, ad libitum
- Water: Municipal tap water, ad libtium
- Acclimation period: at least 5 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 19°C
- Humidity (%): 53 to 64%.
- Air changes (per hr): Ten or greater air changes per hour with 100% fresh air (no air recirculation)
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark cycle
IN-LIFE DATES: From: 2020-01-13 To: 2020-02-07 - Route of administration:
- oral: gavage
- Vehicle:
- arachis oil
- Details on exposure:
- PREPARATION OF DOSING SOLUTIONS:
Test item dosing formulations (w/w) were homogenized to visually acceptable levels at appropriate concentrations to meet dose level requirements. The dosing formulations were prepared daily as a solution and dosed within 24 hours after adding the vehicle to the test
VEHICLE
- Justification for use and choice of vehicle: Selected based on trial preparations
- Concentration in vehicle: 80, 240, 800 mg/mL
- Amount of vehicle (if gavage): 1.25 mL/kg
- Specific gravity: 0.885 - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The concentrations of all groups were analysed using a validated analytical procedure. The formulations of Groups 2 and 4 (sampled from the top, middle and bottom, respectively) were chacked for homogeneity.
- Concentration Analysis: The concentrations analyzed in the formulations of Groups 2, 3 and 4 were in agreement with target concentrations (i.e. mean accuracies between 85% and 115%). A small response at the retention time of the test item was observed in the chromatograms of the Group 1 formulation prepared for use in Week 1. The response was comparable to responses for blank cyclohexane and therefore considered not to derive from test item.
- Homogeneity: The formulations of Groups 2 and 4 were homogeneous (i.e. coefficient of variation ≤ 10%). - Details on mating procedure:
- - Impregnation procedure:purchased timed pregnant
- Duration of treatment / exposure:
- From Day 7 to Day 28 post-coitum
- Frequency of treatment:
- Once daily, 7 days a week
- Dose / conc.:
- 100 mg/kg bw/day (actual dose received)
- Remarks:
- Group 2
- Dose / conc.:
- 300 mg/kg bw/day (actual dose received)
- Remarks:
- Group 3
- Dose / conc.:
- 1 000 mg/kg bw/day (actual dose received)
- Remarks:
- Group 4
- No. of animals per sex per dose:
- 22
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: The dose levels were selected based on the results of the dose range finder, and in an attempt to produce graded responses to the test item. No toxicity and no malformations were observed in the dose range finder and therefore, 1000 mg/kg/day was selected as the highest dose level for the main study.
- Maternal examinations:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: in the morning and at the end of the working day.
- Cage side observations checked for general health/mortality and moribundity were included.
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once daily, beginning on Day 7 post-coitum and lasting up to the day prior to necropsy.
BODY WEIGHT: Yes
- Time schedule for examinations: on Days 7, 9, 12, 15, 18, 21, 24, 27 and 29 post-coitum.
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/animal/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Water consumption was monitored on regular basis throughout the study by visual inspection of the water bottles/containers.
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice: Females surviving to planned necropsy: Day 29 post-coitum. Female with early delivery (No. 69): Within 24 hours of early delivery.
- Organs examined: ovary and uterine horn - 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 and distribution of live and dead fetuses: Yes
- Number and distribution of embryo-fetal deaths: Yes - Fetal examinations:
- - External examinations: Yes: all per litter
- Visceral examinations: Yes: all per litter
- Soft tissue examinations: Yes: approximately half of the fetuses per litter
- Skeletal examinations: Yes: all per litter - Statistics:
- All statistical tests were conducted at the 5% significance level. All pairwise comparisons were conducted using two sided tests and were reported at the 1% or 5% levels.
- Parametric:
Datasets with at least 3 groups (the designated control group and 2 other groups) were compared using Dunnett-test (many-to-one-t-test).
- Non-Parametric:
Datasets with at least 3 groups were compared using a Steel-test (many-to-one rank test).
Mean litter proportions (percent of litter) of the number of viable and dead fetuses, early and late resorptions, total resorptions, pre- and postimplantation loss, and sex distribution were compared using the Mann Whitney test.
Mean litter proportions (percent per litter) of total fetal malformations and developmental variations (external, visceral and skeletal), and each particular external, visceral and skeletal malformation or variation were subjected to the Kruskal-Wallis nonparametric ANOVA test to determine intergroup differences.
- Incidence:
An overall Fisher’s exact test was used to compare all groups at the 5% significance level. The above pairwise comparisons were conducted using a two-sided Fisher’s exact test at the 5% significance level if the overall test was significant.
No statistics were applied for data on maternal survival, pregnancy status, group mean numbers of dead fetuses, early and late resorptions, and pre- and postimplantation loss. - Clinical signs:
- effects observed, treatment-related
- Description (incidence and severity):
- Reduced faeces production was recorded at increased incidence and severity over the dose groups, when compared with the control group, and occurred from Day 1 of treatment onwards at 1000 mg/kg/day.
Other clinical signs noted during the treatment period included scabs, red staining of the vagina, red fluid on manure tray, alopecia, diarrhoea, quick breathing, and a hunched posture. These findings occurred within the range of background findings to be expected for rabbits of this age and strain which are housed and treated under the conditions in this study and did not show any apparent dose-related trend. At the low incidence observed, these were considered to be unrelated to treatment. - Mortality:
- mortality observed, non-treatment-related
- Description (incidence):
- No mortality occurred during the study period that was considered to be related to treatment with the test item.
Female No. 70 (1000 mg/kg/day) was sacrificed in extremis on Day 21 of post-coitum as she had minimal to no food consumption and persistent body weight loss (up to 11%) from the initiation of treatment onwards. Clinical signs included moderate to severe reduced faeces production from the first day of treatment onwards, pale faeces from Day 6 of treatment onwards, piloerection on Days 7, 14 and 15 and a lean posture on Days 13-15 of treatment. At macroscopic examination, the animal was emaciated and the stomach had a reddish discoloration and many gray-white foci. As the condition of the female was more severe than the health condition of the remainder of high dose females, and minimal to absent food consumption with concurrent body weight loss is occasionally observed in rabbits, the preterm sacrifice of this female was considered unrelated to treatment.
Female No. 69 (1000 mg/kg/day) was sacrificed on Day 23 of post-coitum as organic material was found on the manure tray which is a sign of abortion. This animal presented with moderate reduced faeces production for several days, had lost 4% of its body weight from Day 18 until 21 post-coitum and lower food consumption from Day 18 until 23 post-coitum. No macroscopic findings were noted at necropsy. As this was the only animal with an abortion, which is occasionally observed in rabbits, the preterm sacrifice of this female was considered unrelated to treatment.
Female Nos. 48, 49 and 57 (300 mg/kg/day) were sacrificed in extremis on Day 12, 22 and 10 of post-coitum, respectively, as a result of oral gavage incidents.
For female No. 48, a small amount of blood was found on the dosing tube the day before sacrifice but no clinical signs were present. On the day of sacrifice, the animal had labored respiration and minimal food consumption. Macroscopic findings were heart grown together with the lungs and thymus, many reddish foci on the right caudal lobe and black-brown discoloration of the right medial and left lobe of the lungs, and the thoracic cavity contained watery-cloudy, red-brown fluid and black-brown soft material.
Female Nos. 49 and 57 were gasping directly after dosing, and macroscopic findings includeddark red discoloration of the lungs (No. 49) or left lobe of the lungs (Nos. 57), many dark-red foci on the lungs (No. 57), and hemorrhagic (No. 49) or watery-cloudy (No. 57) fluid in the thoracic cavity.
The findings in these animals were indicative for oral gavage incidents and therefore were considered unrelated to treatment with the test item. - Body weight and weight changes:
- no effects observed
- Description (incidence and severity):
- Mean body weights, body weight gain and body weight gain corrected for gravid uterus of treated animals remained in the same range as controls over the treatment period.
- Food consumption and compound intake (if feeding study):
- effects observed, non-treatment-related
- Description (incidence and severity):
- Food consumption before or after correction for body weight was similar to the control level over the study period.
The statistical change in absolute food consumption at 300 mg/kg/day during Days 12-15 post-coitum was considered to be unrelated to treatment since no trend was apparent regarding dose and duration of treatment. - Number of abortions:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Only one female at 1000 mg/kg/day aborted or delivered.
- Pre- and post-implantation loss:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Pre- and post-implantation loss had no significantly different from control group
- Early or late resorptions:
- effects observed, non-treatment-related
- Description (incidence and severity):
- One female of the control (No.29) and one female at 1000 mg/kg/day (No. 76) had early resorptions only. In absence of a dose response, this was not related to treatment with the test item.
Late resorptions at 300 and 1000 mg/kg/day were significantly different from the control group. - Dead fetuses:
- effects observed, non-treatment-related
- Description (incidence and severity):
- Dead fetuses observed at 100 and 300 mg/kg/day, but had no significantly different from control group
- Changes in number of pregnant:
- effects observed, non-treatment-related
- Description (incidence and severity):
- One female of the control (No. 21), two females at 100 mg/kg/day (Nos. 23 and 34), two females at 300 mg/kg/day (Nos. 45 and 54), and two females at 1000 mg/kg/day (Nos. 70 - euthanized on Day 21, and 85) were not pregnant. The incidence of non-pregnancy did not show a relationship to treatment with the test item and was within the historical control range.
- Details on maternal toxic effects:
- The numbers of corpora lutea and implantation sites, pre- and post-implantation loss, and early and late resorptions in the control and test groups were similar and within the range of normal biological variation.
- Dose descriptor:
- NOAEL
- Effect level:
- > 1 000 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Basis for effect level:
- body weight and weight gain
- clinical signs
- food consumption and compound intake
- maternal abnormalities
- mortality
- pre and post implantation loss
- total litter losses by resorption
- Abnormalities:
- effects observed, treatment-related
- Description (incidence and severity):
- Reduced faeces production (up to severe) was observed across animals of all groups, including controls, with a slightly higher incidence and/or severity at 1000 mg/kg/day. In absence of effects on food consumption and/or body weights overall, the reduced faeces production was considered not adverse.
- Fetal body weight changes:
- effects observed, treatment-related
- Description (incidence and severity):
- The mean fetal weight for females was slightly, but statistically significantly, increased at 1000 mg/kg/day (1.10x of control). Similarly, mean fetal male and combined (male and female) weights were (not statistically significant) increased at 1000 mg/kg/day. As the observed changes were considered relatively slight, the increase in fetal weights was considered to be of no toxicologically relevance.
- Changes in sex ratio:
- no effects observed
- Description (incidence and severity):
- The male:female ratio was unaffected by treatment up to 1000 mg/kg/day.
Mean sex ratios (males:females) were 48:52, 48:52, 49:51 and 49:51 for the control, 100, 300 and 1000 mg/kg/day groups, respectively. - Changes in litter size and weights:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There were no test item-related effects on litter size of any group.
Mean litter sizes were 8.8, 9.2, 9.2 and 8.8 viable fetuses/litter for the control, 100, 300 and 1000 mg/kg/day groups, respectively.
One female at 100 mg/kg/day (No. 37) had 15 fetuses of which 8 were viable and 7 were dead. As this was a single occurrence and in absence of a dose response, this was considered unrelated to treatment with the test item. - External malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There were no treatment-related effects on external morphology following treatment with the test item up to 1000 mg/kg/day.
External malformations were observed in one control fetus and four fetuses at 100 mg/kg/day. The control fetus (No. A012-07) and three fetuses at 100 mg/kg/day (Nos. A024-06, A030-11, and A031-06 (dead)) had carpal or tarsal flexure(s). An underlying skeletal abnormality was only found for the carpal flexure of fetus No. A030-11 that missed the radius.
There were two late resorptions with uni- or bilateral carpal flexures. One from the control group (No. A015-09) and the other at 300 mg/kg/day (No. A059-10) that also had a narrow pelvis. The group distribution of carpal and/or tarsal flexures does not indicate a relationship with treatment and as it is at the top of external malformations in historical control fetuses, it was considered a chance finding.
One dead fetus at 100 mg/kg/day (No. A037-03) had cyanose of both hind limbs at external examination that could be linked with the cardiac abnormality noted at visceral examination. Due to single occurrence, this was not related to treatment with the test item.
A late resorption at 300 mg/kg/day had gastroschisis (No. A063-14) and another at 1000 mg/kg/day had multiple malformations (No. A078-02). Due to the single occurrence, both these cases were considered not related to treatment with the test item.
External variations were not observed in this study. - Skeletal malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There were no treatment-related effects on skeletal morphology following treatment with the test item up to 1000 mg/kg/day.
Four fetuses at 1000 mg/kg/day had a skeletal malformation. Fetus Nos. A071-10 and A078-03 each had a vertebral anomaly, and as three control fetuses (Nos. A005-3, A013-4 and A016-6) had this malformation as well, it was considered not related to treatment with the test item.
The two other fetuses at 1000 mg/kg/day with a skeletal malformation were littermates (Nos. A074-06 and -08) that both had a costal cartilage anomaly, which was also the case in 100 mg/kg fetus No. A032-10 (accompanied with a sternal anomaly). Due to the low incidence and previous occurrence in historical control fetuses and in absence of a doserelated trend in incidence, both these malformations were considered chance findings.
No skeletal variations that occurred were considered related to treatment with the test item as they occurred at low incidences, in the absence of a dose-related incidence trend, in control fetuses only and/or at frequencies that were within or near the range of available historical control data. - Visceral malformations:
- effects observed, non-treatment-related
- Description (incidence and severity):
- There were no treatment-related effects on visceral morphology following treatment with the test item up to 1000 mg/kg/day.
Among live fetuses, visceral malformations occurred in 1 (1), 7 (4), 1 (1) fetuses (litters) at the control, 100 and 300 mg/kg/day, respectively, and not at the high dose level.
One 300 mg/kg/day fetus (No. A060-06) had tetralogy of Fallot, which also occurred in fetus No. A030-05 at 100 mg/kg/day. As this malformation occurred singly and previously in historical control fetuses, it was considered a chance finding.
At 100 mg/kg/day, malformations in the remaining six live fetuses were diverse, affecting the cardiovascular system (Nos. A030-1-7), kidneys (Nos. A030-11, A032-10 and A035-7), testes (Nos. A033-7 and A035-7) and/or gallbladder (A035-7). Most of these abnormalities were listed in historical control data and due to the occurrence in the low dose group at single or low incidences all were considered chance findings.
In addition, several visceral malformations occurred in 5 out of 7 dead fetuses from 100 mg/kg/day litter No. A037, but this was considered a maternal or hereditary cause rather than a test item-related effect.
The affected control fetus (No. A010-11) had a spleen abnormality.
All variations noted were considered unrelated to treatment as they occurred in the absence of a dose-related trend, infrequently, in control fetuses only and/or at frequencies that were within or near the range of available historical control data. - Dose descriptor:
- NOAEL
- Effect level:
- > 1 000 mg/kg bw/day (actual dose received)
- Based on:
- test mat.
- Sex:
- male/female
- Basis for effect level:
- changes in sex ratio
- fetal/pup body weight changes
- changes in litter size and weights
- external malformations
- skeletal malformations
- visceral malformations
- Abnormalities:
- effects observed, treatment-related
- Description (incidence and severity):
- Fetal female (statistically significant), male and combined (not statistically significant) body weights were increased at 1000 mg/kg/day. As changes were considered relatively small, the increase was considered to be of no toxicologically relevance.
- Developmental effects observed:
- no
- Conclusions:
- Based on the results in this prenatal developmental toxicity study, the maternal and developmental No observed Adverse Effect Level (NOAEL) for test item was established as being at least 1000 mg/kg/day.
- Executive summary:
The objectives of this study were to determine the potential of test item to induce developmental toxicity after maternal exposure during the critical period of organogenesis and to characterize maternal toxicity at the exposure levels tested as described in OECD 414.
Time-mated female New Zealand White rabbits were treated with test item from Day 7 to Day 28 post-coitum, inclusive by daily oral gavage at dose levels of 100, 300 and 1000 mg/kg/day. The rabbits of the control group received the vehicle, Arachis Oil, alone.
Test formulations prepared were considered homogeneous at the concentrations tested, and analysis of the accuracy revealed acceptable levels.
No mortality was observed during this study that was considered related to treatment with the test item.
One female (No. 70, 1000 mg/kg/day) was sacrificed preterm on Day 21 post-coitum based on prolonged absent food consumption and concurrent body weight loss. In addition, the animal had piloerection and a lean posture for several days of treatment. As the condition of this female was more severe than the health condition of the remainder of the high dose females, and absent food consumption with concurrent body weight loss is occasionally observed in rabbits, the preterm sacrifice of this female was considered unrelated to treatment with the test item.
One female (No. 69, 1000 mg/kg/day) had an abortion, which is occasionally observed in rabbits and therefore, this single incidence of abortion was considered unrelated to treatment with the test item.
Three females were sacrificed preterm (Nos. 48, 49 and 57, 300 mg/kg/day) due to oral gavage incidents.
Reduced faeces production (up to severe) was observed across animals of all groups, including controls, with a slightly higher incidence and/or severity at 1000 mg/kg/day. In absence of effects on food consumption and/or body weights overall, the reduced faeces production was considered not adverse.
No toxicologically significant changes were noted in any of the remaining maternal parameters investigated in this study (i.e. macroscopic examination).
Fetal female (statistically significant), male and combined (not statistically significant) body weights were increased at 1000 mg/kg/day. As changes were considered relatively small, the increase was considered to be of no toxicologically relevance.
No test item-related changes were noted in any of the developmental parameters investigated in this study (i.e. litter size, post-implantation loss, sex ratio, and external, visceral and skeletal malformations and developmental variations).
In conclusion, based on the results in this prenatal developmental toxicity study, the maternal and developmental No observed Adverse Effect Level (NOAEL) for test item was established as being at least 1000 mg/kg/day.
Referenceopen allclose all
Summary and individual tables are provided in "Appendix 1 Figures and Summary Tables" and "Appendix 2 Individual Tables" under Attached background material section.
Historical Control Data are provided in "Appendix 3 Historical Control Data of Fetal Examinations" under Attached background material section.
Effect on developmental toxicity: via oral route
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- NOAEL
- 1 000 mg/kg bw/day
- Study duration:
- subchronic
- Species:
- rat
- Quality of whole database:
- Guideline study, GLP study
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
Pre-natal developmental study in rats:
A pre-natal developmental study with the test substance was conducted according to OECD guideline 414.
The test substance was administered to three groups each of 24 time mated rats between days 5 and 19 of gestation inclusive at dose levels 100, 300 and 1000 mg/kg bw/day. A further group of 24 time mated females were exposed to vehicle only. All surviving females were terminated on day 20 of gestation. The number of corpora lutea, number position and type of implantation, placental weights, foetal weight sex and external and internal macroscopic appearance were recorded.
Oral administration of the test substance did not result in any toxicologically significant effects at any dose level. The NOEL was therefore considered to be 1000 mg/kg bw/day. No toxicologically significant changes were detected in the offspring parameters measured. The NOEL for reproductive and developmental toxicity was therefore considered to be 1000 mg/kg bw/day. The NOAEL was considered to be greater than 1000 mg/kg bw/day.
Pre-natal developmental study in rabbits:
The potential of test item to induce developmental toxicity after maternal exposure during the critical period of organogenesis and to characterize maternal toxicity at the exposure levels tested as described in OECD 414.
Time-mated female New Zealand White rabbits were treated with test item from Day 7 to Day 28 post-coitum, inclusive by daily oral gavage at dose levels of 100, 300 and 1000 mg/kg/day. The rabbits of the control group received the vehicle, Arachis Oil, alone.
No mortality was observed during this study that was considered related to treatment with the test item.
Reduced faeces production (up to severe) was observed across animals of all groups, including controls, with a slightly higher incidence and/or severity at 1000 mg/kg/day. In absence of effects on food consumption and/or body weights overall, the reduced faeces production was considered not adverse.
No toxicologically significant changes were noted in any of the remaining maternal parameters investigated in this study (i.e. macroscopic examination).
Fetal female (statistically significant), male and combined (not statistically significant) body weights were increased at 1000 mg/kg/day. As changes were considered relatively small, the increase was considered to be of no toxicologically relevance.
No test item-related changes were noted in any of the developmental parameters investigated in this study (i.e. litter size, post-implantation loss, sex ratio, and external, visceral and skeletal malformations and developmental variations).
In conclusion, based on the results in this prenatal developmental toxicity study, the maternal and developmental No observed Adverse Effect Level (NOAEL) for test item was established as being at least 1000 mg/kg/day.
Justification for classification or non-classification
Reproductive toxicity:
According to CLP Regulation (Commission Regulation 1272/2008), table 3.7.1 (a), Substances should be classified for reproductive toxicity when there is clear evidence from humans or experimental animals, of an adverse effect on sexual function and fertility, or on development.
As no toxicologically significant effects on sexual function and fertility, or on development in reproductive-developmental screening study, two-generation reproduction toxicity study and prenatal developmental study in rats and rabbits, the substance does not meet the criteria for classification as toxic to reproduction or development.
Effects on or via lactation:
According to CLP Regulation (Commission Regulation 1272/2008), table 3.7.1 (b), substances which are absorbed by women and have been shown to interfere with lactation, or which may be present (including metabolites) in breast milk in amounts sufficient to cause concern for the health of a breastfed child, shall be classified and labelled to indicate this property hazardous to breastfed babies.
As no toxicologically significant effects were noted in reproductive-developmental screening study, two-generation reproduction toxicity study and prenatal developmental study in rats and rabbits, the substance does not meet the criteria for classification.
Additional information
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