2-amino-6-methyl-4-propyl-1,2,4-triazolo[1,5-a]pyrimidin-5(4H)-one

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Non-GLP, available as unpublished report, restrictions in design, the rat as test species is not relevant for the endpoint oral toxicity as rats do not have a vomiting reflex. As a result more of the dosed test substance is available for absorption compared to humans.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

5 rats per sex/dose were exposed to a single dose of 100, 150 or 200 mg/kg bw test substance via oral gavage followed by a 14-day observation period.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-amino-6-methyl-4-propyl-1,2,4-triazolo[1,5-a]pyrimidin-5(4H)-one

EC Number:

248-383-5

EC Name:

2-amino-6-methyl-4-propyl-1,2,4-triazolo[1,5-a]pyrimidin-5(4H)-one

Cas Number:

27277-00-5

Molecular formula:

C9H13N5O

IUPAC Name:

2-amino-6-methyl-4-propyl-1,2,4-triazolo[1,5-a]pyrimidin-5(4H)-one

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

other: albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: males 230 - 304 g and females 175 - 217 g.
- Fasting period before study: 24 hours

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

sorbitan derivative

Remarks:

polysorbate 80

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

Doses:

100, 150, and 200 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 100 - < 150 mg/kg bw

Based on:

test mat.

Mortality:

100 mg/kg bw dose group: no mortality observed.
150 mg/kg bw dose group: three male and four female rats were killed in extremis and one male and one female rat were found dead on days 1 and 2.
200 mg/kg bw dose group: three male and two female rats were killed in extremis and one male and two female rats were found dead on days 1 and 2.

Clinical signs:

other: The most common signs observed at each level included decreased activity, salivation, upward curvature of the spine, increased breathing rate, ptosis and stains around the mouth and nose. The animals in the 100 mg/kg bw dose group all recovered by day 7.

Gross pathology:

No macroscopic abnormalities were seen at necropsy.

Applicant's summary and conclusion

Conclusions:

It can be concluded that the LD50 in rats is between 100 and 150 mg/kg bw.

Executive summary:

Five rats per sex/dose were exposed to a single dose of 100, 150 or 200 mg/kg bw test substance via oral gavage followed by a 14-day observation period. Moderate signs of toxicity were seen following a dose of 100 mg/kg bw. All animals exposed to 100 mg/kg bw test substance had recovered by day 7. Marked signs of toxicity were seen at both 150 and 200 mg/kg bw. The most common signs observed at each level included decreased activity, salivation, upward curvature of the spine, increased breathing rate, ptosis and stains around the mouth and nose. Nine out of ten animals dosed with 150 mg/kg bw and eight out of then dosed with 200 mg/kg bw were found dead or were killed in extremis by day 2. No macroscopic abnormalities were found at necropsy. Under the conditions of the test it can be concluded that the LD50 in rats is between 100 and 150 mg/kg bw.