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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
27 August to 22 October 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: compliance to GLP and testing guideline, coherence between data, results and conclusions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD Guideline 422
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Clear colourless liquid (supplied by Evonik Industries AG, Darmstadt, Germany)
Details on test material:
Name: Butyl diglycol methacrylate

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
A total of 90 Sprague Dawley [Crl:CD(SD)BR] rats (45 males and 45 virgin females), 6 to 7 weeks old and weighing 190 - 217 g for males and 175 - 189 g for females, were received from Charles River Italia S.p.A., Italy.
After arrival the weight range for each sex was determined and the animals were temporarily identified within the cage by means of a coloured mark on the tail. A health check was then performed by a veterinarian.
An acclimatisation period of 13 days was allowed before the start of treatment, during which time the health status of the animals was assessed by thorough observations.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C +/- 2°C
- Humidity (%): 55% +/- 15%
- Air changes (per hr): 15 to 20 air changes per hour
- Photoperiod (hrs dark / hrs light): artificial light for 12 hours each day
No relevant deviations from these ranges were recorded during the study.

In-life phase: August 2013 to 22 October 2013

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
The test item was administered orally by gavage at a dose volume of 5 mL/kg body weight. Control animals received the vehicle alone at the
same dose volume.

The required amount of Butyl diglycol methacrylate was suspended in the vehicle (corn oil) and brought to the final volume appropriate for each
concentration (concentrations of 20, 60 and 200 mg/mL) and kept under magnetic stirrer at room temperature prior to use and until the time of dosing of the last animal.
The formulations were prepared daily and the concentrations were calculated and expressed in terms of test item as supplied.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Prior to commencement of treatment, analysis was performed to confirm that the proposed formulation procedure was acceptable (concentration
and homogeneity). Results of the analyses were within the limits of acceptance.
The stability was found to be 24 hours at room temperature in the concentration range of 20 to 200 mg/mL.
Samples of the formulations prepared on Week 1 and last Week were also analysed to check the concentration and homogeneity. Results of the analyses were within the limits of acceptance.
Chemical analysis was carried out by the Analytical Chemistry Department at RTC according to a validated method (RTC Study No. 96370), in the range from 5 to 200 mg/mL.
Details on mating procedure:
Mating was monogamous (one male to one female). A vaginal smear was taken from the day after the start of pairing until positive identification of
copulation (sperm identification, vaginal plug in situ or copulation plugs found in the cage tray).
The female was paired with the same male until positive identification occurred or 14 days had elapsed.
Duration of treatment / exposure:
Males
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior to pairing and thereafter through the day before necropsy
(Day 29 - 30 of treatment).

Dose volumes were adjusted once per week for each animal according to the last recorded body weight.

Females
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior to pairing and thereafter during pairing, post coitum and
post partum periods until Day 3 post partum (the day before sacrifice).

Dose volumes were adjusted once per week for each animal according to the last recorded body weight.
During the gestation period, dose volumes were calculated according to individual body weight on Days 0, 7, 14 and 20 post coitum and on Day 1
post partum. Thereafter individual dose volumes remained constant.
Frequency of treatment:
once daily
No. of animals per sex per dose:
The test item was administered orally, by gavage. The oral route was selected as it is a possible route of exposure of the test item in man.
3 groups comprised 10 males and 10 females rats received the test item at the dose levels of 100, 300 and 1000 mg/kg/day.
Each group comprised 10 male and 10 female rats.
Control animals:
yes
Details on study design:
Dose levels of 100, 300 and 1000 mg/kg/day were selected by the Sponsor based on information from a previous non GLP compliant study (2 week preliminary study) (RTC Study no.: 96020EXT).

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: No

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before commencement of treatment, at least once daily during the study

BODY WEIGHT: Yes
- Time schedule for examinations: males: weekly from allocation to termination
females: weekly from allocation topositive identification of mating and on gestation days 0, 7, 14 and 20

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
The weight of food consumed by each cage of males and females was recorded weekly during the pre-mating period starting from allocation.
Individual food consumption for the females was measured on gestation Days 7, 14 and 20 starting from Day 0 post coitum and on Day 4 post
partum starting from Day 1 post partum.

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

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day: Day 4 post partum
- Organs examined: please see Annex 1 (Any other information on materials and methods incl. tables)

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
Fetal examinations:
yes
Statistics:
Standard deviations were calculated as appropriate. For continuous variables the significance of the differences amongst group means was assessed by Dunnett’s test or a modified t test, depending on the homogeneity of data.
Statistical analysis of histopathological findings was carried out by means of the non-parametric Kolmogorov-Smirnov test if n was more than 5. The
non-parametric Kruskal-Wallis analysis of variance was used for the other parameters. Intergroup differences between the control and treated
groups were assessed by the non-parametric version of the Williams test. The criterion for statistical significance was p<0.05. The mean values,
standard deviations and statistical analysis were calculated from actual values in the computer without rounding off.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Neuropathological findings:
no effects observed
Description (incidence and severity):
Motot activity and sensory reaction to stimuli revealed in no relevant differences in all parameters investigated between control and treated groups of both sexes.
Histopathological findings: non-neoplastic:
no effects observed

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in number of pregnant:
no effects observed

Effect levels (maternal animals)

Key result
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: developmental toxicity

Results (fetuses)

Fetal body weight changes:
no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Effect levels (fetuses)

Key result
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no effects observed

Fetal abnormalities

Key result
Abnormalities:
no effects observed

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
On the basis of the results obtained in this study with Buty diglycol methacrylate, the NOAEL (No Observed Adverse Effect Level) for
developmental toxicity was found to be 1000 mg/kg/day for males and females.
Executive summary:

In a Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test according to OECD Guideline 422 (22 March 1996) Butyl diglycol methacrylate was administered to 10 Hsd: Sprague Dawley SD rats/sex/dose orally by gavage at dose levels of 0 (control), 100, 300 and 1000 mg/kg bw/d. The treatment schedule included 2 weeks before pairing for males and during pairing with females until the day before necropsy, for a total of 29/30 days. Females were treated for 2 weeks prior to pairing, during pairing and throughout the gestation and lactation periods until Day 3 post partum. The following investigations were performed in all groups: body weight, clinical signs (including neurotoxicity assessment, motor activity and sensory reaction to stimuli), food consumption, oestrous cycle, mating performance, clinical

pathology investigations (haematology and clinical chemistry), litter data, macroscopic observations, organ weights and histopathological examination. Clinical signs and macroscopic observations of pups were also performed. The histopathological examination was performed only on control and high dose groups (five animals/sex/group selected randomly). It included identification of the stages of the spermatogenic cycle in five males.

No animals died during the study. A total of 3 females were found not pregnant at necropsy: 2 in the mid-dose group and 1 in the high dose group. The number of females with live pups on Day 4 post partum was: 10 each in the control ad low dose groups, 8 in the mid-dose and 9 in the high dose groups.

No relevant clinical signs were seen throughout the whole study in treated animals of both sexes.

Clinical observations for neurotoxicity assessment (removal of animals from the home cage and open arena) did not reveal changes attributable to the test item.

Motor activity and sensory reaction to stimuli revealed in no relevant differences in all parameters investigated between

control and treated groups of both sexes.

No differences of toxicological significance in body weight and body weight gain were recorded in animals of both sexes compared to the control group, throughout the study.

Food consumption was unaffected by treatment in both sexes during the study.

Haematology: No changes of toxicological relevance were seen.

Clinical chemistry: No adverse findings were detected at any dose.

All females mated both in the control and treated groups. Oestrous cycle, precoital intervals, copulatory index and fertility index did not show intergroup differences.

Corpora lutea, implantations, pre-implantation and pre-birth loss percentages, total litter size and gestation length did not reveal any treatment-related effect. No differences in total and live litter size, litter weight, mean pup weight and sex ratio were noted between groups at birth and on Day 4 post partum.

Clinical signs noted in pups throughout the study were considered unrelated to treatment.

Necropsy findings in decedent pups and in pups sacrificed on Day 4 post partum did not reveal any treatment-related effect.

Terminal body weight was unaffected by treatment in both sexes. Changes in organ weights were of slight severity and therefore considered of no toxicological significance.

Macroscopic observations: No remarkable changes were noted at post mortem examination in treated animals when compared to controls.

Microscopic observations: No treatment-related findings were observed in high dose males and females.

Conclusions:

This study is acceptable and satisfies the guideline requirement for a Screening reproductive/developmental study according to OECD 422 in rats.

On the basis of the results obtained in this study, the NOAEL (No Observed Adverse Effect Level) for general toxicity was considered to be 1000 mg/kg/day for males and females.

The NOAEL for developmental and reproductive toxicity was also found to be 1000 mg/kg/day for males and females.