2-Heptanol, 3,6-dimethyl-

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29th of May 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

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:

3,6-dimethylheptan-2-ol

EC Number:

801-829-8

Cas Number:

1247790-47-1

Molecular formula:

C9H20O

IUPAC Name:

3,6-dimethylheptan-2-ol

Test animals / tissue source

Details on test animals or tissues and environmental conditions:

Eyes from adult cattle were obtained from a local abattoir as a by-product from freshly slaughtered animals. The eyes were excised by an abattoir employee and placed in Hanks' Balances Salt Solution (HBSS), supplemented with Penicillin/Streptomycin, and transported to the laboratory on ice packs. The corneas were prepared immediately on arrival.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable (control corneas were treated with the negative control)

Amount / concentration applied:

Each three corneae were exposed to 0.75 mL of the test item, the negative control (0.9% w/v sodium chloride solution), or the positive control (ethanol) for 10 minutes.

Duration of treatment / exposure:

Each holder was incubated, anterior chamber uppermost, at 32 ± 1 °C for 10 minutes.

Observation period (in vivo):

Not applicable

Number of animals or in vitro replicates:

Not applicable (three corneas were used for each treated series)

Details on study design:

After the application of the test item and control items the holders were gently titled back and forth to ensure a uniform application of the test item over the entire cornea. Each holder was incubated, anterior chamber uppermost, at 32 ± 1 °C for 10 minutes.

At the end of the exposure period the test item and control items were removed from the anterior chamber and the cornea was rinsed three times with fresh complete minimum essential medium (MEM) containing phenol red before a final rinse with complete MEM. The anterior chamber was refilled with fresh complete MEM. A post-treatment opacity reading was taken and each cornea was visually observed.

The holders were incubated, anterior chamber facing forward, at 32 ± 1 °C for 120 minutes.

After incubation the holders were removed from the incubator and a final opacity reading was taken. Each cornea was visually observed.

Following the opacity measurement the permeability of the corneas to soidum fluorescein was evaluated. The medium from the anterior chamber was removed and replaced with 1 mL of sodium fluorescein solution (4 mg/mL). The dosing holes were plugged and the holders incubated, anterior chamber uppermost, at 32 ± 1 °C for 90 minutes.

After the incubation in the posterior chamber each holder was decanted and retained.

360 µL of medium reoresenting each cornea was applied to a designated well on a 96 well plate and the optical density at 492 nm was measured.

If values greater than 1.500 OD492 were obtained a 1 in 5 dilution of the medium in complete MEM was performed and the measurement repeated. The modified value was multiplied by 5 to reflect the 1 in 5 dilution.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: In Vitro Irritancy Score Test Item

Basis:

mean

Score:

14.8

Reversibility:

other: not applicable

Results 2

Irritation parameter:

other: In Vitro Negative Control

Basis:

mean

Score:

8.9

Reversibility:

other: not applicable

Results 3

Irritation parameter:

other: In Vitro Irritancy Score Positive Control

Basis:

mean

Score:

31.8

Reversibility:

other: not applicable

Any other information on results incl. tables

Individual and mean corneal opacity measurements and individual and mean corneal permeability measurements are given in table 1 attached.

The condition of each cornea post treatment and at the final opacity measurement is given in table 2 attached.

The corneas treated with the test item were clear post treatment and cloudy post incubation. The corneas treated with the test negative control item were clear post treatment and post incubation. The corneas treated with the positive control item were cloudy post treatment and post incubation.

Applicant's summary and conclusion

Interpretation of results:

other: The test item was considered not to be an ocular corrosive or sever irritant

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The test item was considered not to be an ocular corrosive or severe irritant.

Executive summary:

A study was performed to assess the ocular irritancy potential of the test item to the isolated bovine cornea.

The undiluted test item was applied for 10 minutes followed for an incubation period of 120 mintes. Negative and positive controls ites were tested concurrently. The two endpoints, decreased light transmission through the cornea (opacity) and increased passage of sodium fluorescein dye through the cornea (permeability), were combined in an empirically derived formula to generate an In Vitro Irritancy Score (IVIS).

Interpretation:

A test item that induces an In Vitro Irritancy Score ≥ 55.1is defined as an ocular corrosive or sever irritant.

Results. The In Vitro irritancy scores are summarized as follows:

Treatment	In Vitro Irritancy Score
Test Item	14.8
Negative control	8.9
Positive Control	31.8

The test item was considered not to be an ocular corroseve or severe irritant.