2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridine carboxylate; imazapyr (ISO)

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-12-18 to 2013-03-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Bioassay Labor für biologische Analytik GmbH, Im Neuenheimer Feld 515/519, 69120 Heidelberg, Germany

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: COD-001701
- Expiration date of the lot/batch: 2014-11-01
- Purity test date: 2012-10-24

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature (or cooler)

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 9 weeks
- Weight at study initiation: 170 g to 194 g
- Fasting period before study: 16 h before administration
- Housing: single (Makrolon cage, type III
- Diet: VRF1(P); SDS Special Diets Services, 67122 Altrip, Germany (ad libitum)
- Water: tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 to 70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: 2013-01-14 to 2013-02-05

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 20 g/100 mL
- Purity: 0.5% solution in deionised water

MAXIMUM DOSE VOLUME APPLIED: 10 mL

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: request of the sponsor

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: Recording of clinical signs several times on the day of administration, and at least once daily thereafter each workday for the individual animals.
- Frequency of weighing: Individual body weights shortly before administration (day 0), weekly thereafter and on the last day of observation.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

Not applicable

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

discriminating dose

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Mo mortality occurred

Clinical signs:

In the first 2000 mg/kg bw test group impaired general state and piloerection were observed in two animals from hour 2 until hour 5 after administration. One animal did not show any symptoms.
In the second 2000 mg/kg bw test group no clinical signs were observed during clinical examination in all animals.

Body weight:

The mean body weight increased within the normal range throughout the study period. Two animals showed only a small weight gain during the second post-exposure week.

Gross pathology:

There were no macroscopic pathological findings at the end of the observation period.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met