2-Propenoic acid, 2-methyl-, 7-oxabicyclo[4.1.0]hept-3-ylmethyl ester

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

{7-oxabicyclo[4.1.0]heptan-3-yl}methyl 2-methylprop-2-enoate

EC Number:

688-147-2

Cas Number:

82428-30-6

Molecular formula:

C11 H16 O3

IUPAC Name:

{7-oxabicyclo[4.1.0]heptan-3-yl}methyl 2-methylprop-2-enoate

Test material form:

liquid

Details on test material:

- Name: 3,4-Epoxycyclohexylmethyl methacrylate
- Chemical Name: 2-Propenoic acid, 2-methyl-7-oxabicyclo[4.1.0]hept-3-ylmethyl ester
- CAS No.: 82428-30-6
- Physical State / Colour: liquid / light yellow, transparent
- Density: 1.079 g/mL at 20 °C
- Molecular Weight: 196.2 g/mol

Test animals / tissue source

Species:

other: Bovine Corneas

Strain:

other: not applicable

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

750 µL

Duration of treatment / exposure:

10 min

Duration of post- treatment incubation (in vitro):

- 2 h (opacity measurement)
- 3.5 h total (determination of optical density)

Number of animals or in vitro replicates:

3 corneas

Details on study design:

- 3 corneas for the test item
- 3 corneas as negative controls treated with physiological saline 0.9% NaCl
- 3 corneas as positive control treated with ethanol 100%
- The BCOP assay is considered to be valid if the in vitro irritation score obtained with the positive control falls within the two standard deviations of the current historical mean.

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Run / experiment:

mean test item

Value:

10.16

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

IVIS 2.08

Positive controls validity:

valid

Remarks:

IVIS 86.02

Any other information on results incl. tables

RESULTS

Cornea No.	Test Item	Corr. Opacity	Corr. OD490	IVIS
1	Neg. Control	0.00	0.027
2	Neg. Control	4.00	0.021
3	Neg. Control	1.00	0.035
mean	Neg. Control	1.67	0.028	2.08
4	Pos. Control	50.33	1.919
5	Pos. Control	64.33	2.053
6	Pos. Control	53.33	2.031
mean	Pos. Control	56.00	2.001	86.02
7	Test Item	13.33	-0.001
8	Test Item	9.33	-0.022
9	Test Item	8.33	-0.012
mean	Test Item	10.33	-0.011	10.16

The following mean in vitro irritation score was calculated: 10.16

No prediction can be made regarding the classification of the test substance 3,4-Epoxycyclohexylmethyl methacrylate according to the evaluation criteria. Further testing in another suitable method is required.

The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid.

HISTOPATHOLOGY

Negative control samples did not show any histological lesions.

In positive control samples, the main lesions consisted of vacuolated corneal epithelia and single cell apoptosis. In one sample (PK1), there was a marked epithelial flattening/height reduction associated with a focal chronic injury. This corneal sample is deemed to be affected before study start by an inflammatory/degenerative that is supported by the presence of brownish pigment (hemosiderin). In sample PK 3, there was a slight laceration of the cuboidal basal cell layer.

In test item treated samples, there was slight multifocal apoptosis/necrosis in the epithelium of all specimens.

Applicant's summary and conclusion

Interpretation of results:

other: Irritation score of 10.16 and histopathological findings indicate slight signs of irritation

Remarks:

Criteria used for interpretation of results: BCOP standard evaluation criteria

Conclusions:

No prediction can be made regarding the classification of the test substance 3,4-Epoxycyclohexylmethyl methacrylate according to the evaluation criteria. Further testing in another suitable method is required.
Under the conditions of this study, 3,4-Epoxycyclohexylmethyl methacrylate caused indicators for irritation consisting of slight multifocal apoptosis/necrosis associated with multifocal vacuolation in the epithelium of all specimen.

Executive summary:

The eye irritancy potential of 3,4-Epoxycyclohexylmethyl methacrylate was investigated in the bovine corneal opacity and permeability assay.

- Preparation of the test item: tested as provided by the sponsor

- Mean in vitro irritation score: 10.16

- Classification: No prediction can be made

The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid.