Perboric acid, sodium salt

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

10486-00-7

EC Number:

600-611-8

Cas Number:

10486-00-7

IUPAC Name:

10486-00-7

Details on test material:

-Name of test material (as cited in study report): Sodium Perborate Tetrahydrate
-Physical state: White crystalline powder
-Composition of test material, percentage of components (% weight): Active Oxygen: 10.06, Na2O: 20.15, B2O3: 23.07
-Purity test date: September 30, 1994
-Lot/batch No.: I 18.5.94
-Expiration date of the lot/batch: May 18, 1999

Test animals

Species:

rat

Strain:

other: CRL:CD (SD) BR

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Source: Charles River, Italy
-Age at study initiation: ca. 11 weeks
-Weight at study initiation: 200 - 225 g at receipt
-Fasting period before study: none
-Housing: Makrolon cages type 3D
-Diet: ad lib.
-Water: ad lib.
-Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
-Temperature (°C): 22 +/- 2
-Humidity (%): 60 +/- 20
-Air changes (per hr): 10-15
-Photoperiod: 12 hrs dark / 12 hrs light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
-Every day exact amounts of the test item were suspended with the vehicle to obtain the desired concentrations for dose groups 2, 3 and 4 and stirred until administration
-Applied volume: 10 mL/kg bw/d (calculated for each animal on the basis of the last bodyweight recorded)

VEHICLE
- 1 % Methylcellulose 400 cps aqueous solution

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability and homogeneity investigations were performed by a method as provided by the Study Sponsor. Results showed that stability was maintained over 2 hours at concentrations of 10 and 200 mg/mL.
Concentrations of the dosing formulations were checked twice throughout the study with deviations from nominal of less than +/- 5%

Details on mating procedure:

At the start of the mating period, the cages of males were alternated in dose proximity with the cages of females. Every evening (4 evenings/week) the 2 females of each cage were mated with one sexually mature male for 16 hours at a time. Every morning, a vaginal smear was taken with a metal loop from each female and examined at the microscope, to ascertain copulation. The day on which the presence of spermatozoa was found was considered day 0 of pregnancy for that female.
At each daily check, those dams having positive smears were distributed to the experimental groups, one per group by increasing group number. The following day, at the smear check the distribution was resumed where it was left off the day before, in order to evenly complete each dosage group as copulated females were ascertained. In order to be sure to have 20 gravid dams per group, 25 copulated females were allocated to each of the four groups.

Duration of treatment / exposure:

days 6 to 15 of gestation (day 0 = positive vaginal smear)

Frequency of treatment:

once daily

Duration of test:

until day 20 of gestation (caesarean-section / necropsy)

Doses / concentrations

Remarks:

Doses / Concentrations:
0. 100, 300 and 1000 mg/kg bw/day
Basis:
nominal conc.

No. of animals per sex per dose:

25 pregnant females

Control animals:

yes, concurrent vehicle

Details on study design:

Dose selection rationale: doses were selected from a pre-study

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: yes (once daily)

DETAILED CLINICAL OBSERVATIONS: yes (once daily for physical appearance, behaviour and clinical signs)

BODY WEIGHT: yes (on days 0, 6 - 16, 18 and 20 of gestation)

FOOD CONSUMPTION: yes (for each animal determined as left over food on days 6 - 16, 18 and 20 of gestation in order to calculate the mean food consumption in g/animal)

POST-MORTEM EXAMINATIONS: yes (organs examined: all organs with special emphasis to the gastro-intestinal tract)

Ovaries and uterine content:

The following parameters were recorded:

-gravid uterus weight
-number of corpora lutea
-number of implantations
-number of resorptions (early: only placenta visible; late: placenta and embryo visible)
-number and sex of viable foetuses
-number and sex of dead foetuses (foetuses without spontaneous movements and breathing)
-individual foetus weight
-individual placental weight

The uteri of apparently non-pregnant females were stained using the method of Salewski and examined for the presence of early resorption sites.

Fetal examinations:

A gross external examination was performed on all foetuses immediate1y. The externally malformed foetuses were fixed in order not to lose the evidence of malformation. Half of the foetuses per litter were c1eared and examined for skeletal malformations, anomalies and variants. The remaining half of the foetuses were preserved in Bouin's fluid for examination by the Wilson technique.

As far as possible, the distribution per litter for examination by clearing or by Wilson's technique was equal by sex. The observations were classified as follows:
malformations: rare and/or usually lethal (such as hydrocephaly, thoracocele, acephalia, amelia, phocomelia, celosomia etc.)
anomalies: more frequent and not lethal (such as reduced cranial ossification, haemorrhages etc.)
variants: common in the control populations and often definable only in terms of continuous variable gradients: i.e. poor ossification of sternebrae, pubis or other.

Statistics:

Heterogeneity test (Chi sqare)
Fisher's exact test
Probability trend test
Other test were peformed if indicated as either:
Dunnet test or U-test by Man-Whitney

Indices:

Number and sex of viable foetuses
Number of and sex dead foetuses
Individual foetal weights
Individual placenta weights
Fertility index
Pre-implantation loss index
Post-implantation loss index

Historical control data:

yes

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Effects on mean body weight gains and food consumption (reductions) in dams at >= 300 mg/kg bw/day

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

ca. 100 mg/kg bw/day (actual dose received)

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
300 mg/kg bw/d: increase in resorptions, reduction in fetal body weights and placenta weights
1000 mg/kg bw/d: increase in malformations were increased (mainly related to the skeletal and to the cardiovascular system)

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

ca. 100 mg/kg bw/day (actual dose received)

Basis for effect level:

other: fetotoxicity

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The NOAEL for maternal and foetal toxicity was at 100 mg/kg bw/day after oral administartion to pregnant rats from day 6 to 15 of gestation.

Executive summary:

In a developmental toxicity study according to OECD Guideline 414, Sodium Perborate Tetrahydrate was given by the oral route (gavage) to 25 pregnant rats from day 6 to day 15 of gestationat dosages of 0, 100, 300 and 1000 mg/kg bw/day.

There were no clinical signs or behavioral changes and no deaths during the study. A statistically significant dose-related lower mean body weight gain and mean daily food consumption was observed in the >= 300 mg/kg bw/d groups, where a dose-related increase of resorptions and dose-related lower mean fetal and placental weight was also found. At 1000 mg/kg bw/d also an increase of malformations (mainly related to the skeletal and to the cardio-vascular system) was present.

At 100 mg/kg bw/d no biologically significant changes were found both in dams and foetuses.