[No public or meaningful name is available]

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

16.04.2009 - 29.04.2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

up-and-down procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-Amino-5-cyano-N,3-dimethylbenzamide

Cas Number:

890707-29-6

Molecular formula:

C10H11N3O

IUPAC Name:

2-Amino-5-cyano-N,3-dimethylbenzamide

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Raleigh, North Carolina
- Age at study initiation: Approximately 10-11 weeks old
- Weight at study initiation: 196.2–243.1 g
- Fasting period before study: 16-18 hours prior to dosing
- Housing: Animals were housed singly in stainless steel, wire-mesh caging that contained enrichment (e.g., nestlet or nylabone).
- Diet: PMI Nutrition International, LLC Certified Rodent LabDiet (#5002), ad libitum
- Water: Tap water, ad libitum
- Acclimation period: At least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26
- Humidity (%): 30-70
- Air changes (per hr): Not recorded
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

0.1% Tween-80 in 0.5% aqueous methylcellulose

Details on oral exposure:

VEHICLE
- Amount of vehicle: 20 mL/kg

Doses:

175 or 550 mg/kg bw

No. of animals per sex per dose:

3 female rats per dose

Control animals:

no

Details on study design:

A single oral dose of the test substance, suspended in 0.1% Tween-80 in 0.5% MC, was administered by intragastric intubation to fasted female rats at a dose of 175 or 550 mg/kg bw. The animals were dosed one at a time at a minimum of 48-hour intervals. The animals were observed for clinical signs just before dosing, once during the first 30 minutes after dosing and 2 more times within 4 hours after dosing, and once each day thereafter. The animals were weighed on test Days -1, 0, 7, and 14. All animals were euthanised and necropsied to detect grossly observable evidence of organ or tissue damage.

Statistics:

A software package (A0T425StatPgm) was used to determine the dose progression and to calculate the LD50.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

310 mg/kg bw

Based on:

test mat.

Mortality:

Death occurred in all 3 rats dosed at 550 mg/kg.

Clinical signs:

other:

Body weight:

lower than 10% body weight loss

Remarks:

There were no body weight effects noted.

Gross pathology:

No test substance-related gross lesions were found in the study. Gross lesions observed were nonspecific and occurred in low (mostly single) incidences and/or are common findings in rats of this strain and age.

Any other information on results incl. tables

Table 1: Acute oral toxicity of IN-L8E22: Dose progression and mortality

Test sequence	Animal ID	Dose (mg/kg bw)	Short-term result	Long-term result
1	1644	175	O	O
2	1650	550	X	X
3	1654	175	O	O
4	1700	550	X	X
5	1720	175	O	O
6	1722	550	X	X

(X = Died, O = Survived)
Dose Recommendation: The main test is complete.
Stopping criteria met: 5 reversals in 6 tests. Likelihood Ratio criterion.

 

Table 2: Acute oral toxicity of IN-L8E22: Summary of long term results

Dose	O	X	Total
175	3	0	3
550	0	3	3
All doses	3	3	6

(X = Died, O = Survived)
Statistical Estimate based on long term outcomes: The LD50 was 310 mg/kg (based on an assumed sigma of 0.5). Approximate 95% confidence interval is 175 to 550 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the conditions of this study, the estimated oral LD50 for the test substance was 310 mg/kg for female rats.
According to the Globally Harmonized System (GHS) of classification and labeling of chemicals and under the conditions of this study, the test substance is classified in Category 4.

Executive summary:

The acute oral toxicity of the test substance was investigated acoording to the OECD Guideline 425 (Up-and-down procedure).

A single dose of the test substance was administered by oral gavage to 6 fasted female rats at a dose of 175 or 550 mg/kg. The rats were dosed one at a time at a minimum of 48 hour intervals. The rats were observed for mortality, body weight effects, and clinical signs for up to 14 days after dosing. All rats were necropsied to detect grossly observable evidence of organ or tissue damage.
The 3 rats dosed at 550 mg/kg were found dead 1 or 2 days after dosing. Clinical signs observed in 2 of the 3 rats dosed at 550 mg/kg included cold to touch; clear ocular discharge; eyelid ptosis; absent, decreased, or black feces; lethargy; prostrate, low, or high posture; erratic breathing; salivation; stained skin/fur; or bright yellow urine. No clinical signs were observed in the remaining rat dosed at 550 mg/kg. Two of the 3 rats dosed at 175 mg/kg exhibited clinical signs including eyelid ptosis, lethargy, stained skin/fur, chromodacryorrhea, or high posture. No clinical signs were observed after test day 2. The remaining rat dosed at 175 mg/kg exhibited no clinical signs during the study. The surviving rats exhibited no body weight losses. No test substance-related gross lesions were found in the study.

Under the conditions of this study, the estimated oral LD50 for the test substance was 310 mg/kg for female rats.