Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06 June - 23 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:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
GLP compliance:
yes
Test type:
acute toxic class method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
White solid

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals and environmental conditions:
Species: Rat
Strain: Sprague Dawley (SD)
Source: Beijing Vital River Laboratory Animal Technology Co., Ltd.
Number of Animals: 12 female animals arrived, and 6 animals were used. The females were nulliparous and non-pregnant.
Age: 51-60 days on arrival, in the range of 56-65 days at the commencement of each animal's dosing
Weight: The body weight range was 212-244 g, at the commencement of its dosing; its weight fell in an interval within ±20% of the mean body weight of any previously dosed animals.

Justification for Test System:
Rats are the preferred species of choice as they were used historically for the safety evaluations studies and are specified in the appropriate test guidelines.

Husbandry
Housing:
Animals were housed in a room in suspended, stainless steel cages. 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. The lighting sequence was 12 hours light, 12 hours dark.

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

Animal Welfare:
Animal use complied with national animal welfare laws and regulations. Animals surviving to the end of the study were anesthetized by C02 and bled by abdominal aorta to death. Their corpse treatments would be entrusted to specialized agencies. The animal care and use activities required for conduct of this study were reviewed and approved by the testing facility Animal Care and Use Committee.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
After· the· acclimatization period all healthy animals were randomly arranged by Excel 2007, and when administered each time three animals in each group were used sequentially. Each animal, at the commencement of its dosing, its weight fell in an interval within ±20% of the mean body weight of any previously dosed animals. Animals withID beginning from 2100 to 2102 were used for the first dosing, and 2200 to 2202 were used for the seconddosing.

Doses:
The dose level of 2000 mg/kg b.w. was selected as the starting dose from one of four fixed dose levels (5, 50, 300, 2000 mg/kg b.w.) and 3 animals were used in each step. The first step dosing was 2000 mg/kg b.w. and no animal died, so 2000 mg/kg b.w, was selected as the second step
dosing.
No. of animals per sex per dose:
3
Control animals:
no
Details on study design:
Mortality/Moribundity Checks:
Inspections were made twice daily, morning and afternoon, during normal working days, and once daily at weekends and public holidays.

Clinical Observations:
Clinical observations were performed once during the first 30 minutes and at 1, 2 and 4 hours after application and then once each day for up to 14 days. General observations were made once daily for the animals which were not administrated with the test item. Careful observations and records of animal fur changes, eyes and mucosa, digestive, respiratory, circulatory, autonomic and central 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.

Body Weights:
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 surviving animals were weighed. Changes in weights were calculated and recorded when survival exceeding one day.

Animal treatment:
Animals surviving to the end of the study were anesthetized by CO2 abdominal aorta to death.

Necropsy:
A gross necropsy was performed on all animals. The necropsy included careful eye examinations of the abdominal, thoracic organs, and· their contents.
Statistics:
Evaluation of Data:
Using the results obtained, the oral toxicity LD50 range for the test item was evaluated. According to GHS criteria for the acute oral toxicity the test item category was given.

Results and discussion

Effect levels
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
Dose Level-The first dosing (2000 mg/kg b.w.): There were no deaths or moribund states during the test.
Dose Level-The second dosing (2000 mg/kg b.w.): There were no deaths or moribund states during the test.
Clinical signs:
Dose Level-The first dosing (2000 mg/kg b.w.): There were no abnormal findings after dosing from the dosing day until the end of the test. ·
Dose Level-The second dosing (2000 Ing/kg b.w.): There were no abnormal findings after dosing from the dosing day until the end of the test.
Body weight:
The results indicated that all of the animals gained body weights during the study.
Gross pathology:
No abnormalities were found in all animals under test at necropsy.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the results, the acute oral LD50 in rats for Difluorosulfonamide HCl was estimated to be more than 2000 mg/kg b.w. According to the GHS's classification criteria for acute oral toxicity, the test item was not classified.