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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Remarks:
based on generations indicated in Effect levels (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study according to GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2,2'-(cyclohexylimino)bisethanol
EC Number:
224-809-5
EC Name:
2,2'-(cyclohexylimino)bisethanol
Cas Number:
4500-29-2
Molecular formula:
C10H21NO2
IUPAC Name:
2,2'-(cyclohexylimino)bisethanol
Constituent 2
Reference substance name:
2,2`-(cyclohexylomino)bisethanol
IUPAC Name:
2,2`-(cyclohexylomino)bisethanol
Test material form:
other: liquid

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Wistar rat, Crl: WI(Han) (SPF), Charles River, Germany
- Age at study initiation: 9-10 weeks old (males and females)
- Weight at study initiation: 249-288 g (males); 185-213 g (females)
- Fasting period before study: over night
- Housing: individual housing in IVC cages, type III H
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 hourd light / dark

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on mating procedure:
Animals were paired in the ratio 1:1 until evidence of copulation was observed. The females were removed and housed individually when:
- vaginal smear was sperm positive
- a copulation plug was observed
The day of vaginal plug and/or sperm was considered as day 0 of gestation.
All dams were allowed to give birth and rear their litter (F1 pubs) up to day 4 post partum. Day 0 was designated as the day on which a female had delivered all her pubs.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
Males were dosed 28 days
Females were dosed 54 days
Frequency of treatment:
once per day, 7 days per week
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
12 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
30 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
75 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: based on dose-range finder
- Rationale for animal assignment (if not random): random

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: before assignment to groups; males weekly thereafter; females weekly during pre-mating period and on gestation day 0, 7, 14, 20 as well as on post-natal day 4

Sperm parameters (parental animals):
Detailed qualitative examination of the testes including the tubular stages of the spermatogenic cycle
Litter observations:
PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
- number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, survival

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals
- Maternal animals: All surviving animals

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY
- cervix, coagulating gland, epididymis, ovary, prostate, seminal vesicle, testis, uterus, vagina
Postmortem examinations (offspring):
SACRIFICE
- on day 4 post natal

GROSS NECROPSY
- performed on all animals
Reproductive indices:
copulation index, delivery index, fertility index, viability index

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
no effects observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
no effects observed

Effect levels (P0)

Dose descriptor:
NOAEL
Effect level:
>= 75 mg/kg bw/day (actual dose received)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: overall effects

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Body weight and weight changes:
no effects observed
Sexual maturation:
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings:
not examined

Effect levels (F1)

Dose descriptor:
NOAEL
Generation:
F1
Effect level:
>= 75 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: overall effects

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Based on the results of this study, the NOAEL for reproductive toxicity of the test item is equal or greater 75 mg/kg body weight per day.
Executive summary:

Four groups comprised of 10 adult males and 10 non pregnant nulliparous female rats (Wistar Crl:WI) were dosed daily by oral gavage with 12, 30 and 75 mg/kg body weight per day of the test item at dose volume of 5 mL/kg body weight using sterile water as vehicle. Doses were selected based on a dose-range finder study. Control animals were treated identically with the vehicle alone. After 14 days of treatment to both male and female, animals were paired (1:1) till the evidence of mating in the form of sperm positive vaginal smears. Males and females were sacrificed on treatment day 29 and post natal day 4 respectively and subjected to necropsy.

No test item related clinical signs and mortalities were observed in both males and females. Body weight development and food consumption was not affected. Group mean litter weight, total litter weight as well as male and female litter weight on post natal day 0 and 4 was unaffected. No treatment related effect was observed on precoital interval and duration of gestation. Pre and post natal data like group mean number of corpora lutea, percent preimplantation loss and post implantation loss remained unaffected due to treatment when compared with controls. No treatment related effects were observed on reproductive indices like coagulation index, delivery index, fertility index and viability index and there were no effects on litter data like number of males and females, sex ratio and still birth. Survival of pubs from post natal day 0 to 4 remained unaffected and treatment related gross external findings were not observed.

With regard to organ weights, in males a statistical significant decrease in absolute right testes weight in LD group and a decrease in absolute epididymides (right, left and total weight) and relative total epididymides weight in LD and HD group when compared with the controls were revealed. However, since no dose relationship was established and no histopathological changes were observed, no toxicological significance is attributed to these findings. At necropsy of all male and female animals, no macroscopic changes were observed and no treatment-related histopathological findings of reproductive organs were revealed.

A detailed qualitative examination of the testes taking into account the tubular stages of the spermatogenic cycle, revealed no abnormal pathological findings.

In conclusion, the repeated administration of the test item to male animals for 28 days and female animals for a maximum of 54 days revealed no significant toxicological findings and mortalities. Reproductive toxic effects were not revealed. Based on the data, the no observed adverse effect level (NOAEL) for maternal toxicity was equal or greater 75 mg/kg body weight per day. The no observed effect level (NOEL) for reproductive toxicity was equal or greater 75 mg/kg body weight per day.