Methyl phenyl sulphide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 April 2010 to 1 June 2010

Reliability:

1 (reliable without restriction)

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 437: Bovine Corneal Opacity and Permeability (BCOP) test method for identifying ocular corrosives and severe irritants.

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Thioanisole

IUPAC Name:

Thioanisole

Constituent 2

Reference substance name:

Methyl phenyl sulphide

EC Number:

202-878-2

EC Name:

Methyl phenyl sulphide

Cas Number:

100-68-5

Molecular formula:

C7H8S

IUPAC Name:

(methylsulfanyl)benzene

Details on test material:

- Name of test material (as cited in study report): Thioanisole
- Molecular formula (if other than submission substance): Not documented
- Molecular weight (if other than submission substance): 124.19
- Smiles notation (if other than submission substance): Not documented
- InChl (if other than submission substance): Not documented
- Structural formula attached as image file (if other than submission substance): see Fig. Not documented
- Substance type: Not documented
- Physical state: Colourless to slightly yellowish liquid.
- Analytical purity: 99% minimum
- Impurities (identity and concentrations): Not documented
- Composition of test material, percentage of components: Not documented
- Isomers composition: Not documented
- Purity test date: Not documented
- Lot/batch No.: 100310
- Expiration date of the lot/batch: 23rd March 2011
- Radiochemical purity (if radiolabelling): Not documented
- Specific activity (if radiolabelling): Not documented
- Locations of the label (if radiolabelling): Not documented
- Expiration date of radiochemical substance (if radiolabelling): Not documented
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature protected from light under nitrogen.
- Other: Use amber-coloured glassware or wrap container in tin-foil when handling.

Test animals / tissue source

Species:

other: Bovine

Strain:

not specified

Details on test animals or tissues and environmental conditions:

Bovine eyes were used as soon as possible after slaughter on the same day. Bovine eyes from young cattle were obtained from the slaughterhouse where the eyes were excised as soon as possible after slaughter. Eyes were collected and transported in physiological slaine.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

750 µl

Duration of treatment / exposure:

Not documented

Observation period (in vivo):

Not docuemnted

Number of animals or in vitro replicates:

Not relevant

Details on study design:

All eyes were carefully examined for defects by holding the eyes submersed in physiological saline. Those exhibiting unacceptable defects such as opacity, scratches, pigmentation and neovascularisation were discarded. The isolated corneas were stored at 32 ± 1°C in a petri dish with cMEM containing 1% (v/v) L-glutamine and 1% (v/v) Foetal Bovine Serum. The isolated corneas were mounted in a corneal holder (one cornea per holder) of MC2 with the endothelial side against the O-ring of the posterior half of the holder. The anterior half of the holder was positioned on top of the cornea and tightened with screws. The compartments of the corneal holder were filled with cMEM of 32 ± 1°C. The corneas were incubated for the minimum of 1 hour at 32 ± 1°C.

After the incubation period, the medium was removed from both compartments and replaced with cMEM. Opacity determinations were performed on each of the corenas using an opacitometer. The opacity of each cornea was read against an air filled chamber and the initial opacity reading thus determined was recorded. Corneas that had an initial opacity reading higher than 3 were not used. Three corneas were selected at random for each treatment group.

The medium from the anterior compartment was removed and 750ul of the negative and positive control substance were introduced on the epithelium of the cornea. Corneas were incubated in a horizontal position for 10 ± 1 minutes at 32 ± 1°C. After the incubation, the control or test substance was removed and the epithelium was washed at least three with cMEM. The medium in the posterior compartment was removed and both compartments were refilled with fresh cMEM. Subsequently the corneas were incubated for 120 ± 10 minutes at 32 ± 1°C. After the completion of the incubationperiod, opacity determination was performed. Each cornea was inspected visually for dissimilar opacity patterns.

The opacitometer determined the difference in light transmission between each control or treated cornea and an air filled chamber. The change in opacity for each individual cornea was calculated by subtracting the initial opacity reading from the final post treatment reading. The mean opacity value of each treatment group was calculated by averaging the corrected opacity values of treated corneas for each treatment group.

Following the final opacity measurement, permeability of the cornea to Na fluorescein was evaluated. The medium of both compartments was removed and the posterior compartment was refilled with fresh cMEM. The anterior was filled with 1ml of 4mg Na-fluorescein/ml cMEM solution. Corneas were incubated in a horizontal position for 90 ± 5 minutes at 32 ± 1°C.

After the incubation period, the medium in the posterior comaprtment of each holder was removed and placed into a sampling tube. 360ul of medium from each sampling tube was transferred to a 96 well plate. The optical density at 490nmof each sampling tube was measured in triplicate using a microplate reader.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

other:

Time point:

other: 10 minutes

Score:

> 2.8 - < 4.9

Max. score:

4.9

Reversibility:

fully reversible within: 10 minutes

Results 2

Irritation parameter:

other: mean irritancy score

Basis:

mean

Score:

3.9

Reversibility:

not specified

Remarks on result:

other: The test substance did not induce ocular irritation.

Irritant / corrosive response data:

Corneas treated with Thioanisole showed opacity values ranging from 3 to 5 and permeability values ranging from -0.004 to -0.013. The corneas were clear after the 10 minutes of treatment with Thioanisole. Hence, the in vitro irritancy scores ranged from 2.8 to 4.9 after 10 minutes of treatment with Thioanisole.

Other effects:

No additional information

Any other information on results incl. tables

No additional information provided

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a study conducted by Verspeek-Rip (2010), a screening test examining the eye irritancy potential of Thioanisole was conducted using the Bovine Corneal Opacity and Permeability test (BCOP test). The possible ocular irritancy of Thioanisole was tested through topical application for 10 ± 1 minutes. The test substance was applied undiluted at a concentration of 750 230l directly on top of the corneas. Following treatment with Thioanisole, ocular irritation was not apparent, with a mean in vitro irritancy score of 3.9 after 10 minutes of treatment. Based on these results, the test substance was not considered to be a severe irritant or corrosive.

Executive summary:

In a study conducted by Verspeek-Rip (2010), a screening test examining the eye irritancy potential of Thioanisole was conducted using the Bovine Corneal Opacity and Permeability test (BCOP test). The possible ocular irritancy of Thioanisole was tested through topical application for 10 ± 1 minutes. The test substance was applied undiluted at a concentration of 750 230l directly on top of the corneas. Following treatment with Thioanisole, ocular irritation was not apparent, with a mean in vitro irritancy score of 3.9 after 10 minutes of treatment. Based on these results, the test substance was not considered to be a severe irritant or corrosive.