[No public or meaningful name is available]

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1972

Report date:

1972

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, calcium salt

EC Number:

215-710-8

EC Name:

Silicic acid, calcium salt

Cas Number:

1344-95-2

IUPAC Name:

Silicic acid, Calcium salt

Test material form:

solid

Test animals

Species:

mouse

Strain:

CD-1

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation:
- Weight at study initiation: no data
- Fasting period before study: no
- Housing: single
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data
- Humidity (%): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: water suspension

VEHICLE
- Justification for use and choice of vehicle: used as dispersant
- Concentration in vehicle: depending on the dose
- Amount of vehicle: 1 mL suspension/kg bw (Tab. 1, p. 2) [note: not conclusive, is supposed to read 10 mL/kg b.w., comp. corresponding report on NAS]

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: no data
- Length of cohabitation: no data
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

from day 6 to day 15 of gestation

Frequency of treatment:

1x/d

Duration of test:

gestation day 17: sacrifice of all dams by Caesarian section

Doses / concentrations

Dose / conc.:

1 600 mg/kg bw/day (nominal)

No. of animals per sex per dose:

20 - 23 pregnant dams

Control animals:

yes, sham-exposed

other: positive control dosed with Aspirin [150 mg/(kg bw*d)]

Details on study design:

- Other: Sham control is said to be dosed with corn oil, see Tab. 1, p. 2
(probably erroneous, contradicting corresponding report on NAS)

Examinations

Maternal examinations:

BODY WEIGHT: Yes
- Time schedule for examinations: gestation day 0, 6, 11, 15, and 17 (Tab. 4, p. 6)

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes (not documented)
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 17
- Organs examined: in particular urogenital tract

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes (neonatal pup weight) [Appendix II, p. 8]
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of resorptions: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: 1/3 per litter
- Skeletal examinations: Yes: 2/3 per litter
- Head examinations: Yes

Statistics:

no data

Historical control data:

no data

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Remarks:

(highest dose tested)

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: highest dose tested

Maternal abnormalities

Key result

Abnormalities:

no effects observed

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: highest dose tested

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Applicant's summary and conclusion

Conclusions:

The administration of up to 1600 mg/kg bw/day of the test material to pregnant mice for 10 consecutive days had no clearly discernible effect on nidation or on maternal or fetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.