2,4-Thiophenedicarbonitrile, 5-amino-3-methyl-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 January 2010 and 4 February 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

yes

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

yes

Principles of method if other than guideline:

No analysis was conducted to determine the homogeneity, concentration or stability of the test material formulation. This is an exception with regard to GLP and has been reflected in the GLP compliance statement.
This exception is considered not to affect the purpose or integrity of the study.

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

5-amino-3-methylthiophene-2,4-dicarbonitrile

EC Number:

610-868-8

Cas Number:

52603-48-2

Molecular formula:

C7N3H5S

IUPAC Name:

5-amino-3-methylthiophene-2,4-dicarbonitrile

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Limited, Bicester, Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non-pregnant.
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 163 - 178 g. The bodyweight variation did not exceed ± 20% of the initial/mean bodyweight of any previously dosed animal(s).
- Fasting period before study: overnight immediately before dosing and 3-4 hours after dosing
- Housing: groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days
The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25°C
- Humidity (%): 30 to 70%
Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study.
- Air changes (per hr): at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (06:00 to 18:00) and twelve hours darkness

IN-LIFE DATES: From: 12 January 2010 To: 4 February 2010

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 mg/ml
- Amount of vehicle (if gavage): 10 ml/kg
- Justification for choice of vehicle: the test material did not dissolve/suspend in distilled water, therefore arachis oil was used as an alternative
- Lot/batch no. (if required): NDA
- Purity: NDA

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

DOSAGE PREPARATION (if unusual): For the purpose of the study the test material was freshly prepared, as required, as a suspension in arachis oil BP.
The test material was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.
No analysis was conducted to determine the homogeneity, concentration or stability of the test material formulation.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: In the absence of data suggesting the test material was toxic, 300 mg/kg was chosen as the starting dose.

Doses:

In the absence of data suggesting the test material was toxic, 300 mg/kg was chosen as the starting dose.
In the absence of mortality but presence of evident toxicity at a dose level of 300 mg/kg, an additional group of 4 animals was treated.
A total of five animals were therefore treated at a dose level of 300 mg/kg in the study.

No. of animals per sex per dose:

5 females at 300 mg/kg

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made 0.5, 1, 2, and 4 hours after dosing and subsequently once daily for fourteen days. Morbidity and mortality checks were made twice daily.
Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

The test material will be classified according to Annex 3 of the OECD Guidelines for Testing of Chemicals No. 420 "Acute Oral Toxicity - Fixed Dose Method" (adopted 17 December 2001) as shown in the attached Flow Chart.
Evaluation of data included identification of the number of animals that died during the study (or that were killed for humane reasons), and determination of the nature, severity, onset and duration of the toxic effects. If possible, the signs of evident toxicity were described. Evident toxicity refers to the toxic effects of sufficient severity that administration of the next higher dose level could result in development of severe signs of toxicity and probable mortality. Effects on bodyweights and abnormalities noted at necropsy were also identified.
Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test material was made.

Results and discussion

Preliminary study:

A preliminary animal was dosed at 300 mg/kg, and in the absence of mortality but presence of evident toxicity at this dose level, an additional group of four animals was treated at a dose level of 300 mg/kg.

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

300 - 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

other: Signs of systemic toxicity noted were hunched posture, lethargy, pilo-erection, tiptoe gait and ataxia. Animals appeared normal four, five or seven days after dosing.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

None

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test material in the female Wistar strain rat was estimated to be in the range 300 - 2000 mg/kg bodyweight (Globally Harmonised Classification System - Category 4) and Harmful according to the EC Directive 67/548/EEC.

Executive summary:

In an acute oral toxicity study (0656/0411), a group of 5 fasted eight to twelve week old female Wistar strain rats were given a single oral dose of the test substance in arachis oil at a dose level of 300 mg/kg bw and observed for 14 days.

Oral LD50: 300 - 2000 mg/kg bw

No mortality occurred. Signs of systemic toxicity noted during the study were hunched posture, lethargy, pilo-erection, tiptoe gait and ataxia. No abnormalities were noted at necropsy.