Registration Dossier

Toxicological information

Developmental toxicity / teratogenicity

Currently viewing:

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1978-08-21 to 1978-10-06
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Study conducted before internationally agreed test guidelines were applicable and when adherence to GLP principles was not mandatory. Nevertheless, methods, experimental details and results are reported in detail, and the study design is comparable to modern guidelines. Thus, the study is considered as reliable with (minor) restrictions and suitable to derive conclusions for the hazard assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Pregnant New Zealand White rabbits were used to evaluate the teratogenic potential of the test item. The compound was administered dermally from days 7 through 18 of gestation at dosage levels of 500 and 2000 mg/kg/day at a constant volume of 2 mL/kg/day. One control group received the vehicle, distilled water, on a comparable regimen at 2 mL/kg/day. An environmental control group received no treatment. The following parameters were examined in the does: clinical signs, mortality, body weight, pathology, and uterine contents. External, soft tissue, skeletal and head examinations were carried out in the foetuses. The body weight of the foetuses were also recorded.
GLP compliance:
no
Remarks:
at the time of conduct, GLP was not compulsory.
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): T-0311.02
- Physical state: clear liquid
- Analytical purity: 100% of 40% anhydrous ZAGS solution
- Composition of test material, percentage of components: 6.28% Al and 5.78% Zr
- Expiration date of the lot/batch: May 1, 1979
- Storage condition of test material: ambient between 10°C and 32°C; store in glass or plastic
- Density: 1.27 g/mL
- Solubility: soluble
- pH: 3.29

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: approximately 6 months old
- Housing: the rabbits were individually housed in hanging wire mesh cages and maintained in a controlled environment.
- Diet (ad libitum): Purina Rabbit Chow
- Water (ad libitum): tap water
- Acclimation period: 18 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2°C
- Relative humidity: 40% to 60%
- Air changes: 10 to 15 fresh air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12
Temperature , light/dark cycle and air exchange per hour in the rabbit rooms during the study were maintained within the specified limits. The mean relative humidity exceeded the prescribed range by approximately 14% during the study.

Administration / exposure

Route of administration:
dermal
Vehicle:
water
Details on exposure:
TEST SITE
- Area of exposure: the test material was applied to the clipped area of the backs of the females and spread evenly using a glass rod.
- Time intervals for shavings or clipplings: the backs of the females were clipped before applying the test material, and at three day intervals thereafter throughout the treatment period.

USE OF RESTRAINERS FOR PREVENTING INGESTION:
At the time of dosing, the females were fitted with an Ejay Saf-T Shield collars (obtained from W. A. Butler, Inc., Columbus, Ohio) to prevent oral ingestion of the test material.

The environmental control females were not clipped, cleaned or fitted with collars.

REMOVAL OF TEST SUBSTANCE
- Washing: the collars were removed from the rabbits and the compound was cleaned from the collars, cages and the backs of the rabbits by wiping with a damp towel.
- Time after start of exposure: four hours after compound administration

TEST MATERIAL &
- Amount(s) applied (volume or weight with unit): 2 mL/kg/day
- Constant volume or concentration used: yes, constant volume

VEHICLE
The vehicle control group received the vehicle, distilled water, at 2 mL/kg/day.

Individual dosages were based on individual body weights taken on days 7, 10, 13 and 16 of gestation.

VEHICLE - distilled water
- Amount(s) applied (volume or weight with unit): 2 mL/kg/day of the vehicle was given to the vehicle control group.





Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
none
Details on mating procedure:
- Impregnation procedure: artificial insemination
Five proven male rabbits of the same strain were selected to serve as semen donors. Semen from one male was used to insemicate 4 females on a given day (1 female from each dosage level.).
Semen was collected by means of an artificial vagina (obtained from the Holborn Surgical Instrument Co., Ltd., London, England). The gelatinous plug was removed from the ejaculate and the semen was immediatley evaluated for motality. Semen with 50% or greater motality was diluted with 4.0 mL of 0.9% sodium chloride for Injection U.S.P. at 35°C. The minimum concentration of motile sperm in the dilutions used for insemination was 12 x 10^6/mL. One-fourth to 1/2 mL of dilute semen was introduced into the anterior vagina of each female with an insemination pipette (obtained from the Holborn Surgical Instrument Co., Ltd., London, England). Ovulation was induced with 100 units of A.P.L (Ayerest Laboratories, Inc., New York, N.Y.)(human chorionic gonadotropin) administered intravenously via the marginal ear vein within one hour of insemination.
The day of insemination was designated day 0 of gestation.
Insemination procedures were performed on 10 separate days. Two females from each dosage level were inseminated per day.
Duration of treatment / exposure:
days 7 through 18 of gestation
Frequency of treatment:
single daily dose
Duration of test:
28 days
No. of animals per sex per dose:
20 female rabbits
Control animals:
yes, concurrent vehicle
other: environmental control group
Details on study design:
not applicable

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: prior to treatment, the females were observed daily for mortality and overt changes in appearance and bahviour. The females were observed daily for mortality and clinical signs of toxicity from gestation days 7 through 28.

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: individual female body weights were recorded on days 0, 3, 7, 10, 13, 16, 19, 22, 25 and 28 of gestation.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- 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): No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day #28
All female rabbits were sacrificed by an overdose of Socumb C II (sodium pentobarbital)(W. A. Butler Company, Columbus, Ohio) via injection into the marginal ear vein. Immediatley following sacrifice, the foetuses were delivered by cesarean section and the thoracic and abdominal cavities and organs of the does were examined.
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of total implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other:
The number and location of viable and nonviable foetues were recorded.
Fetal examinations:
- External examinations: Yes, all foetuses
- Soft tissue examinations: Yes, all foetuses
- Skeletal examinations: Yes, all foetuses
- Head examinations: Yes all foetuses

All foetuses were individually weighed, tagged and examined for external malformations and variations, including the palate and eyes. Each foetus was dissected, internally sexed and examined for visceral malformations and variations, including the brain by a mid-coronal slice. The heart was dissected by a modification of the method described by R.E. Staples (1974)*. The eviscerated, skinned foetuses were fixed in alcohol, macerated in potassium hydroxide and stained with Alizarin Red S by a method similar to that described by Dawson (1926)* for subsequent skeletal examination.

*References:
Staples, R.E. (1974) Detection of Visceral Alterations in Mammalian Foetuses, Teratology, 9: A37 - A38.
Dawson, A.B. (1926), A Note on the Staining of the Skeleton of Cleared Specimens with Alizarin Red S, Stain Technol., 1: pp 123 - 124.
Statistics:
Any statistical analyses that may become necessary will be done by the sponsor.
Indices:
none
Historical control data:
none

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:no effects

Details on maternal toxic effects:
Nasal discharge was frequently noted in all groups in this study and is not considered to be treatment related. Maternal external observations between environmental control group and the vehicle control group was comparable. Reddening at the site of compound application was noted in several rabbits in the 500 mg/kg/day dosage group, and scabbing at the application site was also noted in one of these rabbits. Reddening at the site of compound application was noted in most of the rabbits in the 2000 mg/kg/day dosage group, and some of these rabbits were also noted as having chracking, scabbing or swelling at the application site. No effect was noted at the site of compound application in the vehicle control group. Survival was 100% in all groups.
Mean maternal body weight gains between the environmental control groups and the vehicle control group were comparable. There were no biologically meaningful differences in mean maternal body weight gains between either of the test item treated groups and the control groups.
The mean number of early and late resorptions, post implantation losses, implantations, and corpora lutea in the environmental control group and the vehicle control group were comparable. A decrease in the mean number of viable foetuses was noted in the vehicle control group when compared to the environmental control group. There were no biologically meaningful differences in the mean number of viable foetuses, early and late resorptions, postimplantation losses, implantations, and corpora lutea between either of the test item treated groups and the control groups.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
2 000 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks on result:
not determinable due to absence of adverse toxic effects

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The mean foetal body weights and the male and female foetal sex ratio in the environmental control group and the vehicle control group were comparable. There were no biologically meaningful differences in the mean foetal body weights or in the male to female sex ratio between either of the test item treated groups and the control groups.
An increase in the number of foetuses and number of litters with malformations was noted in the environmental control group when compared to the vehicle control group. There were no biologically meaningful differences in the number of foetuses or number of litters with malformations between either the test item treated groups and the control groups. Variations were comparable for all groups.

Effect levels (fetuses)

open allclose all
Dose descriptor:
NOAEL
Effect level:
2 000 mg/kg bw/day (nominal)
Based on:
test mat.
Basis for effect level:
other: teratogenicity
Dose descriptor:
NOAEL
Effect level:
126 mg/kg bw/day (nominal)
Based on:
element
Remarks:
Al
Basis for effect level:
other: teratogenicity
Dose descriptor:
NOAEL
Effect level:
116 mg/kg bw/day (nominal)
Based on:
element
Remarks:
Zr
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
NOAEL > 2000 mg/kg/day (nominal)
The test item did not produce a teratogenic effect when administered to rabbits dermally at dosage levels of 2000 mg/kg/day or less.