1H,5H-Pyrazolo(1,2-a)pyrazol-1-one, 2,3-diamino-6,7-dihydro-, dimethanesulfonate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 September 2006 - 09 October 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: compliant to GLP and testing guideline; adequate coherence between data, comments and conclusions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): R0054002C, synonym IMEXINE OBH
- Physical state: beige to yellow powder
- Purity: 99.7%
- Impurities (identity and concentrations): not indicated
- Purity test date: 20 July 2006
- Lot/batch No.: R0054002C 013 L 001, synonym 0604070001
- Expiration date of the lot/batch: 01 August 2007
- Stability under test conditions: not indicated
- Storage condition of test material: at room temperature and under nitrogen gas

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: breeder Janvier, Le Genest-Saint-Isle, France
- Age at first treatment: 11 weeks
- Weight at first treatment (mean): 304 g
- Housing: individually
- Diet: ad libitum, SsniffR/M-H pelleted maintenance diet
- Water: ad libitum, tap water (filtered with a 0.22 µm filter)
- Acclimation period: 4-5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Relative humidity: 50 ± 20%
- Light/dark cycle: 12h/12h
- Ventilation: 12 cycles/hour of filtered, non-recycled air.

IN-LIFE DATES: beginning: 17 September 2006 / end: 8 October 2006

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: purified water, obtained by reverse osmosis

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a solution in the vehicle. The test item was mixed with the required quantity of vehicle in order to achieve the concentrations of 20, 60 and 200 mg/mL and then homogenized using a magnetic stirrer.

VEHICLE
- Concentration in vehicle: 20, 60 and 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg/day

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

determined in samples taken from each dosage form (including the control) prepared for use on the first day of dosing of the first animal and on the last day of dosing of the study - HPLC/UV

Details on mating procedure:

- Impregnation procedure: purchased time pregnant
- Proof of pregnancy: vaginal plug

Duration of treatment / exposure:

day 6 to day 20 post-coitum

Frequency of treatment:

once daily

Duration of test:

21 days

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg/day (f)
Basis:
actual ingested

No. of animals per sex per dose:

24 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: no effects on dams and development at up to 1000 mg/kg/day in a range-finding study
- Rationale for animal assignment: stratified procedure based on body weight recorded on day 2 post coitum, to ensure comparatively similar mean body weights among groups

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule: regularly at 3- to 4-day intervals

FOOD CONSUMPTION: Yes
- Food consumption for each animal determined daily: Yes

WATER CONSUMPTION: No

POST-MORTEM MACROSCOPIC EXAMINATION: Yes
- Sacrifice on gestation day# 21
- Examined: principal thoracic and abdominal organs

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: number of uterine scars, gross evaluation of placenta

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: half per litter
- Other : number dead and live, body weight, sex

Indices:

% Pre-implantation loss = 100 * (Number of corpora lutea - Number of implantation sites) / Number of corpora lutea
% Post-implantation loss = 100 * (Number of implantation sites - Number of live fetuses) / Number of implantation sites

Historical control data:

Not provided; not required for interpretation of the data obtained

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
Reddish colored bedding was noted in all test item-treated females (probably related to the test item). At 1000 mg/kg/day, two females showed signs of poor clinical condition (loud and abdominal breathing and/or excessive salivation).

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Not required (no effects)

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Not required (no effects). Satisfactory agreement between measured and nominal contents in administered dosage forms.

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) was considered to be 1000 mg/kg/day for maternal and developmental toxicity.

Executive summary:

The test item was administered daily, from day 6 to day 20 post-coitum, by the oral route (gavage), to mated female Sprague-Dawley rats at dose-levels of 100, 300 or 1000 mg/kg/day.

There were no mortalities nor any effects on maternal body weight gain or food consumption. Clinical signs were limited to reddish colored bedding (all treated females) and signs of poor clinical condition in only two high-dose females.

There were no treatment-related effects on pregnancy parameters (numbers of corpora lutea, implantation and live fetuses) nor on fetal body weight or sex.

There were no effects of treatment on fetal sex, mean fetal body weight or fetal development; no test item treatment-related external, visceral or skeletal malformations or variations were observed.