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

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 June - 03 July, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Rabbits are the preferred species of choice as historically used for the safety evaluation studies and are specified in the appropriate test guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: GHS

GLP compliance:

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 / tissue source

Species:

rabbit

Strain:

other: Japanese white

Remarks:

Albino

Details on test animals or tissues and environmental conditions:

- Age at study initiation: Young adults, 84 days at receipt and approximately 91 to 93 days old at dosing
- Weight at study initiation: Body weights ranged from 1724.3 to 2167.9 g at receipt and 1932.9 to 2484.5 at dosing
- Housing: Individually housed in cages
- Diet: Pelleted diet for rabbits available ad libitum
- Water: Free access to tap water
- Acclimation period: For 7 to 9 days prior to dosing

ENVIRONMENTAL CONDITIONS (set to maintain)
- Temperature (°C): 17-23
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye of each animal remained untreated and served as the referene control

Amount / concentration applied:

0.1 g of test item was placed in the conjunctival sac of right eye of each animal

Duration of treatment / exposure:

Each animal was dosed once

Observation period (in vivo):

Both eyes of all animals were examined using a binocular loupe at approximately 1, 24, 48, and 72 hours or until the 6th day after administrations. The ocular reaction for conjunctivae, cornea, and iris were recorded at each examination. Any other lesions in the eye were also reported.

Immediately after administration of the test material, the initial reaction was observed and recorded. Test animals were routinely observed and recorded for clinical signs of pain and/or distress and any adverse systemic effects except eye twice daily for 3 days after administration of the test material, with a minimum of 6 hours between observatoins (two animals were observed until the 4th and 6th days after administrations, with once daily observations from the 4th day until hte end of the observation period.

Number of animals or in vitro replicates:

3 males

Details on study design:

STUDY DESIGN
Initial Testing: Testing was initially conducted in one animal
Confirmatory Test: A corrosive or severe irritant effect was not observed in the initial test, the confirmatory test was conducted using two additional animals sequentially.
The time interval between the initial and confirmatory tests was approximately 24 hours.

TREATMENT
Approximately 24 hours prior to dosing, both eyes of each animal were examined with binocular loupe and 2% aqueous sodium fluorescein (vehicle: physiological saline) in the slit lamp. One drop of 2% aqueous sodium fluorescein was place dinthe conjunctivae sac of both eyes, and then eyes were washed using physiological saline after 15 seconds. Corneas of both eyes were examined in the slit lamp to see whether there was fluorescein detention in the cornea or not.

DOSING
Each rabbit received 0.1 g of the test material in the conjuncitval sac of the right eye. The lids were held together for approximately one second in order to prevent material loss. The left eye remained untreated and served as a control. Each animal was dosed once and in the morning.

OBSERVATIONS
- Clinical: Immediately after administion of the test material, the initial reaction was observed and recorded. Test animals were routinely observed and recorded for clinicals signs of pain and/or distress and any adverse systemic effects except eye twice daily for 3 days after administration of the test material, with a minimum of 6 hours between observations (two animals were observed until 4th and 6th days after administratoins, respectively, with once daily observations from the 4th day until the end of observation period.
-Eye: Both eyes of all animals were examined using a binocular loupe at approximately 1, 24, 48, 72 hours, or until the 6th day after administration. The ocular reaction for conjunctivae, cornea, and iris were recorded at each examination. Any other lesions in the eye were also reported. Ocular lesions (cornea for opacity, iris, conjunctivae for redness and swelling) of the treated eye of each animal was scored and recorded at each eye examination.
-Fluorescein: Two animals' eyes were not examined by fluorescein sodium and slit lamp after administration as the whole corneas could not be clearly observed due to severe damage. Both eyes of one animal were furhter examined with the aid of fluorescein sodium and slit lamp at approximately 24, 48, and 72 hours after administration.
-Body Weight: Individual animal body weights were recorded within 24 hours after arrival, on the day of dosing, and upon completion of the final observations.
-Histopathology: Histopathological examinations were not conducted as irreversible corrosive reactions were found and al animals were humanely killed by euthenasia.

The surviving animals were humanely killed by 10% KCl injection application (1.5 mL/kg) after anesthia by Zoletil (5 mg/kg) at the end of the study. Their corpse treatements were entrusted to specialized agencies.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal: 1100

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Reversibility:

not reversible

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal: 1101

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Reversibility:

not reversible

Results 3

Irritation parameter:

cornea opacity score

Basis:

animal: 1102

Remarks:

Mean

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not reversible

Results 4

Irritation parameter:

iris score

Basis:

animal: 1100

Remarks:

Mean

Time point:

24/48/72 h

Score:

0.67

Max. score:

2

Reversibility:

not reversible

Results 5

Irritation parameter:

iris score

Basis:

animal: 1101

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Results 6

Irritation parameter:

iris score

Basis:

animal: 1102

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Results 7

Irritation parameter:

conjunctivae score

Basis:

animal: 1100

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Results 8

Irritation parameter:

conjunctivae score

Basis:

animal: 1101

Remarks:

Mean

Time point:

24/48/72 h

Score:

3

Max. score:

3

Results 9

Irritation parameter:

conjunctivae score

Basis:

animal: 1102

Remarks:

Mean

Time point:

24/48/72 h

Score:

3

Max. score:

3

Results 10

Irritation parameter:

chemosis score

Basis:

animal: 1100

Remarks:

Mean

Time point:

24/48/72 h

Score:

3.33

Max. score:

4

Results 11

Irritation parameter:

chemosis score

Basis:

animal: 1101

Remarks:

Mean

Time point:

24/48/72 h

Score:

2.67

Max. score:

3

Results 12

Irritation parameter:

chemosis score

Basis:

animal: 1102

Remarks:

Mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Other effects:

-Clinical Observations: No adverse systemic effect was observed in any animal during the study
-Eye Examination: There were not abnormalities for all eyes in eye examinations approximately 24 hours prior to dosing.
There were no observable abnormalities in eye examinations for three control eyes at all obsersvation intervals after administration.
-Body Weights: All animals showed expected gains in body weights during the study.
-Fluorescein Examination: There was no retention of fluorescein for three treated and ontrol eyes approximately 24 hours prior to dosing. Because the whole corneas of animals 1100 and 1101 could not be observed after administrations (due to severe damages), the fluorescein examinations were not conducted. The treated eye of animal 1102 showed fluorescein retentionwith cornea opacity, with retention area of the whole area at 24, 48, and 72 hours after administration.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

According to the Guidelines for the testing of chemicals "Acute Eye Irritaiton/Corrosion Test" (405) published by the Ministry of Environmental Protection of People's Republic of China in 2013, the test item was considered to produce serious eye damage and irreversible corrosion on the eyes in rabbits, so the animals under test were humanely killed by euthenasia, and the study was terminated.

Executive summary:

Based on the above results, Difluorosulfonamide HCl could produce serious eye damage and irreversible corrosion on the eye in the rabbit, and was classified as "Category 1" according to GHS's classification criteria for eye irritation.