(1R,2R)-1-Amino-2-(difluoromethyl)-N-(1-methylcyclopropylsulfonyl)cyclopropanecarboxamide hydrochloride

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 June - 20 June, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(1R,2R)-1-amino-2-difluoromethyl)-N- (1-methylcyclopropylsulfonyl)cyclo propanecarboxyamide hydrochloride

EC Number:

943-460-6

Cas Number:

1360828-80-3

Molecular formula:

C9H15CIF2N203S

IUPAC Name:

(1R,2R)-1-amino-2-difluoromethyl)-N- (1-methylcyclopropylsulfonyl)cyclo propanecarboxyamide hydrochloride

Test material form:

solid: particulate/powder

Details on test material:

White solid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Species: Rat
Strain: Sprague Dawley (SD)
Source: Beijing Vital River Laboratory Animal Technology Co., Ltd.
Number of Animals: 12 rats (6 males, 6 females)
Age: 51-60 days on arrival, in the range of 56-65 days at the commencement of each animal's dosing
Weight: males: 236-251 g, females: 206-237 g

Justification for Test System and Number of Animals:
Rats are the preferred species of choice as they were historically used for safety evaluations studies and are specified in the appropriate test guidelines.
The Number of Animals: Totally purchased animals were 12 rats (6 females, 6 males), and 10 rats (5 females, 5 males) were selected.
The females were nulliparous and non-pregnant

Animal Identification
All animals were weighed and marked by the special animal markers on the hair from No.1 to 6 in each sex and number written on cage cards within 24 hours after arrival.

Environmental Acclimation
Healthy young adult animals were acclimatized to the laboratory conditions and housed in a room of the facility two per cage for 5 days prior to the
test, and one per cage during the test.

Husbandry
Housing:
Animals were housed in a room of the facility. Animals were raised in suspended, stainless steel cages on cage racks. Animals were housed individually during the test.

Environmental Conditions:
Temperature and humidity were controlled automatically and recorded daily. The values in the animal room were 20-25°C for temperature, and
40%-70% for humidity. A controlled light cycle was 12 hour light, 12 hour dark.

Food and water:
Animals were provided sterilized diet with complete nutrition. Diet and water were available to the animals ad libitum during test.

Animal Welfare:
Animal use complied with national animal welfare laws and regulations. The animal care and use activities required to conduct the
study were reviewed and approved by the testing facility.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

Approximately 24 hours before the test, fur was removed from the dorsal area of the trunk of the test animals by clipping. Care was taken to avoid abrading the skin, which could alter its permeability. The cleared area was about 40 cm, animals with healthy and intact skin were used. Each animal was dosed once. The test item was applied evenly to the treatment area. The gauze was placed over the treatment area and was wrapped with a piece of self-adhesive bandage. Shortly after dosing the dressings were examined to ensure that the animals cannot ingest the test item. At the end of the exposure period for approximate 24 hours, residual test item was removed by cotton wool soaked in water.

Duration of exposure:

24 hrs.

Doses:

A limit test at one dose level of 2000 mg/kg body weight was carried out via dermal route in a group of 10 animals (5 males and 5 females). Clinical observations were made during the first 30 minutes and at 1, 2, and 4 hours after dosing and then once each day for up to 14 days. Individual weights of animals were determined within 24 hours after arrival, at grouping, on Day 0 (day of dosing), Day 7 and Day 14. At the end of the test, a gross necropsy was performed on all animals under test.

No. of animals per sex per dose:

5 per sex per dose (dose: 2000 mg/kg bw)

Control animals:

not required

Details on study design:

Limit Test
A limit test at one dose level of 2000 mg/kg body weight was carried out via dermal route in a group of 10 animals (5 males and 5 females).

Clinical Observations
Clinical observations were performed once during the first 30 minutes and at 1, 2 and 4 hours after application approximately and then once each day for 14 days. Careful observations and records of animal fur changes, eyes and mucosa, respiratory, circulatory, nervous system, particularly limb activity and behavior changes were made. Particular attention was directed to observations of tremor, convulsions, salivation, diarrhea, lethargy, sleep and coma.
All the animals were examined for reaction to dosing. The onset, intensity and duration of these signs was recorded, particular attention being paid to the animals during and for the first hour after dosing.

Skin Irritation:
Adverse skin reactions at the site of application were recorded daily following the removal of the dressings according to the grading of skin reactions:

Erythema and eschar formation:
No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema 4

Edema Formation:
No edema 0
Very slight edema 1
Slight edema 2
Moderate edema 3
Severe edema 4
Severe oedema (raised more than 1 millimeter and extending beyond the area of exposure) 4

Terminal Procedures
All animals were sacrificed by oxygen/carbon dioxide procedure at the end of the observation
period. All animals assigned to the study were subjected to necropsy and descriptions of all
internal macroscopic abnormalities were recorded.

Results and discussion

Preliminary study:

A limit test dose of 2,000 mg/kg-bw/day was selected.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths or moribund states were observed during the test.

Clinical signs:

other: There were no abnormal findings in all animals during the test.

Gross pathology:

No abnormalities were found in all animals at necropsy.

Other findings:

No signs of dermal irritation were observed in all animals during the test.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results, the acute dermal LDso in rats for Difluorosulfonamide HCl was as follows: Male rats: >2000 mg/kg b.w. and Female rats: >2000 mg/kg b.w.
According to the GHS's classification criteria of acute dermal toxicity, the test item was classified as "Unclassified".