(R)-thiazolidine-4-carboxylic acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2023

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(R)-thiazolidine-4-carboxylic acid

EC Number:

252-106-3

EC Name:

(R)-thiazolidine-4-carboxylic acid

Cas Number:

34592-47-7

Molecular formula:

C4H7NO2S

IUPAC Name:

(R)-thiazolidine-4-carboxylic acid

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Label name TCA
Batch number 20190104
Expiry date July 2024
Storage conditions Room temperature

Test system

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

treatment level of 30 µL/tissue unit

Duration of treatment / exposure:

4 h followed by 30 minutes post-soak period

Duration of post- treatment incubation (in vitro):

18 hours

Number of animals or in vitro replicates:

In the Main Assays, the test item was applied as supplied in two replicates at the treatment
level of 30 ±2 mg/tissue unit.

Details on study design:

Before the Main Assay, a preliminary test was carried out to evaluate the compatibility of
the test item with the test system. In a first step, the test item was assayed for the ability of
reducing MTT per se. A white precipitate was noticed, but no colour change was observed
indicating that the test item did not directly interact with MTT. In a second step, the test item
was assayed for the ability of colouring water per se. A colourless solution was observed,
indicating that the test item has no potential interfering ability. Based on these results, no
additional controls were added in the Main Assay.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

mean percent tissue viability 

Run / experiment:

Main assay I

Value:

51

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Since a borderline value was obtained, it was necessary to perform a second Main Assay.

Results 2

Irritation parameter:

mean percent tissue viability 

Run / experiment:

Main Assay II

Value:

24

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Since discordant results were obtained in the first two Main Assays, a third assay was performed.

Results 3

Irritation parameter:

mean percent tissue viability 

Run / experiment:

Main Assay III

Value:

23

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

In Main Assay I the positive control caused the expected cell death (16% of cell viability
when compared to the negative control) and variability (difference of % viability equal to 1).
Based on the stated criteria (mean viability ≤ 20% and difference of cell viability between
each replicate lower than 20%), the assay was regarded as valid. The test item induced cell
death, the mean tissue viability after the blank subtraction was 51% when compared to the
negative control. Intra-replicate variability was acceptable with a difference of % viability
value equal to 1 (lower than 20, as stated in the Study Protocol). Since a borderline value
was obtained, it was necessary to perform a second Main Assay.
In the Main Assay II the positive control caused the expected cell death (4% of cell viability
when compared to the negative control) and variability (difference of % viability equal to 0).
Based on the stated criteria (mean viability ≤ 20% and difference of cell viability between
each replicate lower than 20%), the assay was regarded as valid. The test item induced cell
death, the mean tissue viability after the blank subtraction was 24% when compared to the
negative control. Intra-replicate variability was acceptable with a difference of % viability
value equal to 1 (lower than 20, as stated in the Study Protocol). Since discordant results
were obtained in the first two Main Assays, a third assay was performed.
In the Main Assay III the positive control caused the expected cell death (6% of cell viability
when compared to the negative control) and variability (difference of % viability equal to 0).
Based on the stated criteria (mean viability ≤ 20% and difference of cell viability between
each replicate lower than 20%), the assay was regarded as valid. The test item induced cell
death, the mean tissue viability after the blank subtraction was 23% when compared to the
negative control. Intra-replicate variability was acceptable with a difference of % viability
value equal to 1 (lower than 20, as stated in the Study Protocol).

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Based on the results obtained, the test item L(-)-Thiazolidine-4-carboxylic acid (TCA) is
considered as irritant to the eye.