((4S,4aR,7S,7aR)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 1 - June 8, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

N/A

Molecular formula:

C10H16O2

Test material form:

liquid

Remarks:

Colorless

Details on test material:

Test substance was expected to be stable for the duration of testing.

Specific details on test material used for the study:

- lot number of test material:
CH-DA-01-18

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Stored refrigerated

- Stability and homogeneity of the test material in the vehicle/solvent under test conditions (e.g. in the exposure medium) and during storage:
Test substance was expected to be stable for the duration of testing.

- Stability in the medium, i.e. sensitivity of the test material to hydrolysis and/or photolysis:
The test substance was applied as received

- Solubility and stability of the test material in the solvent/vehicle and the exposure medium:
The test substance was applied as received

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing (e.g. warming, grinding):
Mixed well prior to use

- Preliminary purification step (if any):
None

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Robinson Services, Inc.
- Age at study initiation: 15 - 16 weeks
- Weight at study initiation: 2965 - 3478 grams
- Housing:
The animals were singly housed in suspended stainless steel caging, which conforms to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Enrichment (e.g., toy) was placed in each cage. Litter paper was placed beneath the cage and was changed at least three times per week.

- Diet (e.g. ad libitum):
PMI 5326 High Fiber Rabbit Diet. A designated amount of the diet (approximately 150 grams/day) and alfalfa hay cubes (Grainland Select Alfalfa Cubes) were available to each rabbit.

- Water: Filtered tap water was supplied ad libitum

- Acclimation period: 19 or 33 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 24
- Humidity (%): 49 - 68
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The other eye of each rabbit remained untreated with the test substance and served as a control.

Amount / concentration applied:

One-tenth of a milliliter of the test substance.

Duration of treatment / exposure:

The upper and lower lids were gently held together after instillation for about one second before releasing to minimize loss of the test substance.

Observation period (in vivo):

1, 24, 48, and 72 hours and at 4 and 7 days post-instillation.

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done):
Ocular irritation was evaluated using Draize method of scoring at 1, 24, 48, and 72 hours and at 4 and 7 days post-instillation. The fluorescein dye evaluation procedure (which involves rinsing with physiological saline) was used in the treated eye at 24 hours and as needed at subsequent scoring intervals


SCORING SYSTEM: Draize method

TOOL USED TO ASSESS SCORE: fluorescein

Results and discussion

In vivo

Results

Irritation parameter:

maximum mean total score (MMTS)

Basis:

mean

Remarks:

The time interval with the highest mean score (Maximum Mean Total Score - MMTS) for all rabbits was used to classify the test substance by the system of Kay and Calandra

Time point:

24 h

Score:

14.7

Reversibility:

fully reversible within: 96 hours

Remarks on result:

probability of mild irritation

Irritant / corrosive response data:

Within 24 hours after test substance instillation, two treated eyes exhibited corneal opacity and
‘positive’ conjunctivitis. There was no iritis observed in any treated eye during this study. The
overall incidence and severity of irritation decreased gradually with time. Positive irritation
cleared from the two treated eyes by Day 4. All animals were free of ocular irritation by Day 7
(study termination).
The Maximum Mean Total Score of Dihydronepetalactone is 14.7.

Any other information on results incl. tables

INDIVIDUAL SCORES FOR OCULAR IRRITATION

	Rabbit No.: 3401 (Female)
	Hours				Days
	1	24	48	72	4	7
I. Cornea
A. Opacity	0	2	2	1	0	0
B.Area	4	1	1	1	4	4
(AxB)x5	0	10	10	5	0	0
II. Iris
A.Values	0	0	0	0	0	0
Ax5	0	0	0	0	0	0
III. Conjunctivae
A.Redness	1	2	2	2	1	0
B. Chemosis	2	1	1	0	0	0
C. Discharge	3	1	0	0	0	0
(A+B+C)x2	12	8	6	4	2	0
Total	12	18	16	9	2	0

 

	Rabbit No.: 3402 (Female)
	Hours				Days
	1	24	48	72	4	7
I. Cornea
A. Opacity	0	2	2	1	0	0
B.Area	4	1	1	1	4	4
(AxB)x5	0	10	10	5	0	0
II. Iris
A.Values	0	0	0	0	0	0
Ax5	0	0	0	0	0	0
III. Conjunctivae
A.Redness	1	2	2	2	1	0
B. Chemosis	2	2	1	0	0	0
C. Discharge	3	2	0	0	0	0
(A+B+C)x2	12	12	6	4	2	0
Total	12	22	16	9	2	0

 

	Rabbit No.: 3403 (Female)
	Hours				Days
	1	24	48	72	4	7
I. Cornea
A. Opacity	0	0	0	0	0	0
B.Area	4	4	4	4	4	4
(AxB)x5	0	0	0	0	0	0
II. Iris
A.Values	0	0	0	0	0	0
Ax5	0	0	0	0	0	0
III. Conjunctivae
A.Redness	1	1	0	0	0	0
B. Chemosis	1	1	0	0	0	0
C. Discharge	2	0	0	0	0	0
(A+B+C)x2	8	4	0	0	0	0
Total	8	4	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

Category 2B (mildly irritating to eyes) based on GHS criteria

Conclusions:

Under the conditions of this study, Dihydronepetalactone is classified as mildly irritating to the
eye.

Executive summary:

A primary eye irritation test was conducted with rabbits to determine the potential for Dihydronepetalactone to produce irritation from a single instillation via the ocular route. One-tenth of a milliliter of the test substance was instilled into the right eye of three healthy rabbits. The left eye remained untreated and served as a control. Ocular irritation was evaluated by the Draize method of scoring.Within 24 hours after test substance instillation, two treated eyes exhibited corneal opacity and ‘positive’ conjunctivitis. There was no iritis observed in any treated eye during this study. The overall incidence and severity of irritation decreased gradually with time. Positive irritation cleared from the two treated eyes by Day 4. All animals were free of ocular irritation by Day 7 (study termination).

The Maximum Mean Total Score of Dihydronepetalactone is 14.7. Under the conditions of this study, Dihydronepetalactone is classified as mildly irritating to the eye.