2-Pyridinecarboxylic acid, 4-(acetylamino)-3,6-dichloro-, methyl ester

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 December 2012 to 25 January 2013

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:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

up-and-down procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Appearance: Variable coloured powder
- Storage conditions of the test material: Ambient

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 to 11 weeks
- Weight at study initiation: 170.1 to 192.2 g. The body weight variation of animals was minimal and did not exceed ± 20 per cent of the previously dosed animals.
- Fasting period before study: Yes. Animals were fasted overnight prior to dosing (16 to 18 hours). Access to water was not interrupted and the animals were fed immediately after dosing.
- Housing: Rats were housed individually in standard polysulfone plastic solid-bottom cages (Size: approximately 425 mm long x 266 mm deep x 175 mm high), with stainless steel top grills having facilities for pelleted food and drinking water. Steam sterilised clean corn cob bedding was used and changed along with the cage twice weekly. The rats were provided with huts as environmental enrichment in each cage during the experimental period.
- Diet (e.g. ad libitum): Standard rat and mouse pelleted maintenance diet was provided ad libitum
- Water (e.g. ad libitum): Deep bore-well water passed through activated charcoal filter and exposed to UV rays in a water filter-cum-purifier was provided to animals ad libitum in polycarbonate bottles with stainless steel sipper tubes.
- Acclimation period: Five to fourteen days under standard laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 23 °C
- Humidity (%): 65 to 66 % (relative)
- Air changes (per hr): 12 to 15 air changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours of light and 12 hours of dark

IN-LIFE DATES: From: 28 December 2012 To: 25 January 2013

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Milli-Q water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL as a suspension.
- Justification for choice of vehicle: The test material formed a visibly homogenous suspension in the chosen vehicle.

MAXIMUM DOSE VOLUME APPLIED: The volume administered was 10 mL/kg bodyweight.

DOSAGE PREPARATION: 2 g of the test material was mixed by adding small quantities of Milli-Q water until a final volume of 10 mL was reached. Homogeneity of the test material in the vehicle was maintained during treatment by constant stirring and mixing with a glass rod. Preparations were made prior (within 1 hour) to dosing.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: The limit value was selected as the starting dose.

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 females per dose

Control animals:

no

Details on study design:

- Dosing schedule: Single animals were dosed in sequence. Each subsequent animal was dosed only after assessing the toxicity of the test material to the previously dosed animal.
- Duration of observation period following administration: 14 days following test material administration.
- Frequency of observations and weighing: The animals were observed five times on test day 1 (day of administration), at 30 minutes, 1, 2, 3 and 4 hours after dose administration and once daily during days 2 to 15. Individual body weights of animals were recorded on test day 1 (pre-administration), day 8 (7 days post administration) and day 15 (14 days post administration).
- Necropsy of survivors performed: Yes. All animals were necropsied at the end of the 14-day observation period; animals were sacrificed by exsanguination under isoflurane anaesthesia. External surfaces of the body, all orifices, tissues and organs of the thoracic and abdominal cavities of all animals were examined for gross pathological changes. The stomach was opened, the contents rinsed / removed, and the mucosal surface was examined for signs of irritation, erosions and ulcers. All necropsy observations were recorded.

Results and discussion

Preliminary study:

The limit test at 2000 mg/kg was initiated with one female rat. The first animal survived and there were no clinical signs of toxicity or mortality; hence four additional female rats were tested sequentially at the same dose.

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There was no mortality. All animals exposed to the limit dose survived.

Clinical signs:

other: There were no clinical signs of toxicity in any animal.

Gross pathology:

There were no abnormalities detected at necropsy.

Any other information on results incl. tables

Table 1: Body Weight and Body Weight Changes

Step	Rat Number	Body weight (g)
		Initial (Day 1)	Day 8	Weight change (Day 8 -Initial)	Day 15	Weight change (Day 15 -Initial)
1	Rm1431	170.1	198.6	28.5	207.8	37.7
2	Rm1432	182.5	203.6	21.1	218.9	36.4
3	Rm1433	184.1	209.6	25.5	218.2	34.1
4	Rm1434	184.2	200.8	16.6	219.6	35.4
5	Rm1435	192.2	209.8	17.6	222.1	29.9

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study, the acute oral LD50 was >2000 mg/kg bodyweight in female Wistar strain rats and the test material requires no classification in accordance with EU criteria.

Executive summary:

The acute oral toxicity potential of the test material to female Wistar strain rats was assessed in accordance with the standardised guidelines OECD 425 and US EPA OPPTS 870.1100 under GLP conditions.

The study was initiated with a limit test at 2000 mg/kg with one female rat. The test material was mixed in Milli-Q water and administered as a single oral dose via gavage to fasted rats. The first animal survived, hence four additional animals were tested sequentially with the same dose.

Rats were observed for 14 days post treatment. All animals were sacrificed as scheduled on study Day 15 and subjected to gross necropsy.

There were no clinical signs of toxicity and none of the animals died. All the animals gained body weight during the 14-day observation period. There were no gross abnormalities detected in any of the rats at necropsy.

Under the conditions of this study, the acute oral LD50 was >2000 mg/kg bodyweight and the test material requires no classification in accordance with EU criteria.