3,5-diiodothyronine

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:

2018

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 (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,5-diiodothyronine

EC Number:

213-867-7

EC Name:

3,5-diiodothyronine

Cas Number:

1041-01-6

Molecular formula:

C15H13I2NO4

IUPAC Name:

2-amino-3-[4-(4-hydroxyphenoxy)-3,5-diiodophenyl]propanoic acid

Test material form:

solid

Test system

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Two replicates were tested with 51.4 mg and 49.6 mg of the substance, respectively.

Duration of treatment / exposure:

After dosing the last tissue, all plates were transferred into the incubator for 6 hours at 37 ± 1 °C, 5 ± 1 % CO2 and 80 – 100 % relative humidity.

Duration of post- treatment incubation (in vitro):

At the end of exposure time, the inserts were removed from the plates in one-minute-intervals using sterile forceps and rinsed immediately. The inserts were thoroughly rinsed with DPBS. Then, the tissues were immediately transferred into 5 mL of assay medium in pre-labelled 12-well plate for 25 minutes post soak at room temperature.
After that, each insert was blotted on absorbent material and transferred into a pre-labelled 6-well plate, containing 1 mL assay medium. For post-treatment incubation, the tissues were incubated for 18 hours at 37 ± 1 °C, 5 ± 1 % CO2 and 80 – 100 % relative humidity.

Number of animals or in vitro replicates:

Two replicates were tested.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

Tissue 1

Value:

93.3

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

Tissue 2

Value:

96.8

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

mean value

Value:

95

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

The % viability values of the positive control were:

40.7 % (tissue 1), 35.7 % (tissue 2) and 38.2 % (mean value), respectively.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, L-Tyrosine, O-(4-hydroxyphenyl)-3,5-diiodo- is consid-ered non-eye irritant in the EpiOcularTM Eye Irritation Test.
After treatment with the test item, the mean value of relative tissue viability was reduced to 95.0 %. This value is above the threshold for eye irritation potential (≤ 60%).
All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 2.0 (> 0.8 and < 2.5).
The positive control induced a decrease in tissue viability as compared to the negative control to 38.2%. Variation within the replicates of the controls and the test item was ac-ceptable (< 20%).
For these reasons, the result of the test is considered valid.