2-Propenoic acid, 2-isocyanatoethyl ester

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 April 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, performed under GLP conditions. Study was performed before actual guideline was accepted.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 437 (BCOP test for corrosivity/severe irritation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

MHRA, UK GLP Monitoring Authority

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

482-140-6

EC Name:

-

Cas Number:

13641-96-8

Molecular formula:

Hill formula: C6 H7 N O3 CAS formula: C6 H7 N O3

IUPAC Name:

2-isocyanatoethyl prop-2-enoate

Test animals / tissue source

Species:

other: bos

Strain:

other: not applicable, in vitro test

Details on test animals or tissues and environmental conditions:

In vitro test system, isolated corneas from the eyes of freshly slaughtered cattle were used.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: Negative control sodium chloride

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 µL
- Concentration (if solution): undiluted

Duration of treatment / exposure:

10 min

Observation period (in vivo):

Not applicable, in vitro test system. Additional 2 hours incubation time after rinsing.

Number of animals or in vitro replicates:

Not applicable, in vitro test system. Corneas used in triplicate

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, 5 washes until wash medium was clear
- Time after start of exposure: 10 min

SCORING SYSTEM:
OPACITY MEASUREMENT:
The opacitometer measured the light transmission through the centre of each mounted cornea, displaying a numerical opacity value (arbitrary unit). The opacity of each cornea was measured by reading each holder in the right-hand chamber of the calibrated opacitometer. Once the basal opacity of all the corneas had been measured, the mean basal opacity value was calculated. Any corneas deviating from the mean by more than 3 units were discarded.

After washing and the 2 hour incubation period the opacities of the corneas were determined again. The opacity values obtained at this stage were used in calculating the final In Vitro Score. Throughout the assay the corneas were examined for opaque spots or other irregularities; any atypical characteristics were recorded.

The change in the opacity of each cornea was calculated by subtracting the initial basal opacity from the post-treatment opacity measurement. The mean change in opacity for the negative control corneas was calculated and was subtracted from the change in opacity of each treated cornea to obtain the corrected opacity value. The mean corrected opacity change value of each treatment group (of 3 corneas) was calculated from the individual corrected opacity values of the treated corneas.

PERMEABILITY DETERMINATION:
Following the final opacity measurement, the medium was removed from the anterior compartment of the holder. One mL (1mL) of sodium fluorescein solution was added to the anterior compartment. Following addition of the sodium fluorescein solution to the anterior side of the holder, the compartment was plugged and the corneas incubated in a horizontal position at 32°C ± 2°C for 90 ± 5 minutes in a waterbath.
Following incubation, the medium in the posterior compartment was mixed by drawing approximately 2.5 ml gently up and down a 5 ml syringe, with a needle attached, three times. An aliquot of the mixed medium from the posterior compartment was removed and transferred to a 1 cm path length cuvette. A spectrophotometer was adjusted to read at 490nm (OD490) and a sample of cMEM read (OD =0.066). The spectrophotometer was blanked using this solution prior to reading the permeability samples. Any solution giving an OD490 value above 1.8 was diluted 1 in 5 with cMEM.

The corrected permeability value (OD490) of each treated cornea was calculated by subtracting the mean negative control cornea value from the permeability value of each cornea. The mean corrected permeability value of each treatment group was calculated from the individual corrected permeability values of the treated corneas.

IN VITRO SCORE CALCULATION:
The In Vitro Score was calculated using the following formula:
In Vitro Score = Corrected Opacity Value + (15 x Corrected OD490 Value)
The In Vitro Score was calculated for each individual treatment and positive control cornea. The mean In Vitro Score value for each treatment group was calculated from the In Vitro Scores of each individual cornea in the treatment group.

PREDICTION MODEL:
The test substance was classified as a negative irritant if the In Vitro Score was 0-25 and as a positive irritant if the Score was >25 according to the thresholds developed by Curren et al (1996).

TOOL USED TO ASSESS SCORE: opacitometer, spectrophotometer

Results and discussion

In vitro

Results

Irritation parameter:

other: In Vitro Score

Value:

23.4

Remarks on result:

other: Basis: mean. Time point: 10 min. Reversibility: other: not applicable, in vitro test system. Remarks: Negative (non-irritating)

Other effects / acceptance of results:

When the Threshold Prediction Model (Curren et al.) is applied, the test substance AOI, with an In Vitro Score of 23.4 ± 3.5, is classified as a negative potential eye irritant.

Applicant's summary and conclusion

Interpretation of results:

other: not irritating