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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1976-05-12 to 1976-06-20
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
no
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Sodium Aluminosilicate (Type A Zeolite)
- Chemical name: Zeolite, cuboidal, crystalline, synthetic, non-fibrous
- Framework: cuboidal
- Related CAS number: 1318-02-1
- Analytical purity: no data
- Composition of test material, percentage of components: 16.0% sodium, 40.6% silicone dioxide, 20.1% aluminum and 21% moisture
- Lot/batch No.: UDX-8709

Test animals

Species:
rat
Strain:
Sprague-Dawley

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
20 female rats/ treatment groups were administered 0.0 (solvent control = water), 74.0, or 1600 mg/kg bw test substance from gestation day 6 till day 15. The total volume applied was 10 ml/kg bw for each treatment group.
Analytical verification of doses or concentrations:
yes
Details on mating procedure:
Females were maintained for two weeks before exposure to males, to allow any pseudo-pregnant animals to become sexually receptive. At the end of the two-week period, the females were paired with the males and vaginal smears and observation for plugs were commenced.
Duration of treatment / exposure:
on gestation days 6 - 15
Frequency of treatment:
daily
Duration of test:
Sacrifice of dams: day 20
Doses / concentrations
Remarks:
Doses / Concentrations:
0 (distilled water), 74, or 1600 mg/kg
Basis:
nominal in water
No. of animals per sex per dose:
20
Control animals:
yes, concurrent vehicle
Details on study design:
A positive control was run in parallel (aspirin, 250 mg/kg).

Examinations

Maternal examinations:
The day the vaginal smear showed the presence of sperm was designated day 0 of pregnancy and the male was removed. The females were weighed on days 0, 6, 9, 12, 15, 18 and 20 of gestation.

PARAMETERS ASSESSED DURING STUDY:
- Maternal weight gains: yes
- Mortality: yes
Ovaries and uterine content:
PARAMETERS ASSESSED DURING STUDY:
- Fetal weight gains: yes
- Number of Corpora Lutea: yes
- Number of Implantations: yes
- Number of Resorptions: yes
Fetal examinations:
PARAMETERS ASSESSED DURING STUDY:
- Fetal weight gains: yes
- Examination of fetuses: yes

Results and discussion

Results: maternal animals

Maternal developmental toxicity

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

Details on maternal toxic effects:
The conception rate ranged from 80 to 90% thus assuring a sufficient number of fetuses to assess the teratogenic potential of sodium aluminiumsilicate.
There were no maternal deaths in zeolite treated group, although there were three deaths in the positive control group. Two of those deaths were attributed to the pulmonary aspiration of the aspirin. There were no statistically significant differences in maternal weight gain, which further indicates the lack of maternal toxicity or mortality from zeolite.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
> 1 600 mg/kg bw/day
Basis for effect level:
other: maternal toxicity

Results (fetuses)

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

Details on embryotoxic / teratogenic effects:
Statistical examination of the numbers of corpora lutea, implantations and resorptions revealed no significant differences in the numbers of live or dead fetuses or in the weights of the fetuses. These data show that no embryo or fetal toxicity resulted from the zeolite treatment.
There were no significant differences seen in the incidence of gross or soft-tissue malformations. One fetus in the 74 mg/kg dose group had multi-malformations. Hydronephrosis, often times classified as a variation, occurred in a low percentage in the zeolite treated group. No statistical differences were noted in the incidence of skeletal defects in treated groups, although a significant increase in the overall incidence of skeletal abnormalities occurred in the positive control (aspirin) group.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
> 1 600 mg/kg bw/day
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

The test substance was not teratogenic in rats at these levels tested.

Applicant's summary and conclusion