Sodium 3-[[5-[(diethylamino)sulphonyl]-2-methoxyphenyl]azo]-4-hydroxynaphthalene-1-sulphonate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

other: experimental study on similar substance

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Colipa report n. C174

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Neutral Red Uptake assay (NRU) on human keratinocytes

Deviations:

not specified

Principles of method if other than guideline:

The NRU cytotoxicity assay procedure is a cell survival/viability chemosensitivity assay based on the ability of viable cells to incorporate and bind neutral red (NR), a supravital dye. NR is a weak cationic dye that readily penetrates cell membranes by non-ionic diffusion and accumulates intracellularly in lysosomes. Alterations of the cell surface or the sensitive lysosomal membrane lead to lysosomal fragility and other changes that gradually become irreversible. Such changes brought about by the action of xenobiotics result in a decreased uptake and binding of NR. It is thus possible to distinguish between viable, damaged, or dead cells, which is the basis of this assay.
In several studies for its ability to predict eye irritation potential as reflected by Draize scores. (Guidance Document on Using In VitroData to Estimate In Vivo Starting Doses for Acute Toxicity - ICCVAM)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 6-hydroxy-5-[(2-methoxy-4-sulphonato-m-tolyl)azo]naphthalene-2-sulphonate

EC Number:

247-368-0

EC Name:

Disodium 6-hydroxy-5-[(2-methoxy-4-sulphonato-m-tolyl)azo]naphthalene-2-sulphonate

Cas Number:

25956-17-6

Molecular formula:

C18H16N2O8S2.2Na

Test animals / tissue source

Species:

human

Details on test animals or tissues and environmental conditions:

Human keratinocytes (HaCat).

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

Amount / concentration applied:

3.162 to 10000 µg/ml medium

Duration of treatment / exposure:

24 hours

Details on study design:

Monolayers of human keratinocytes (HaCat) were exposed in 96-well microtiter plates to various concentrations of Curry Red for 24 hours and cell viability was measured by neutral red uptake.
The concentration causing a 50 % reduction in neutral red uptake compared to the concurrent control (NRU-50) is determined. This figure, as a measure for
cytotoxicity of a test item in this cell culture, is compared to findings with known eye irritants under identical test conditions and allows a prediction of the eye irritation potential of a test item.

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Value:

0

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

No NRU-50 value could be determined as the viability was still 71 % in the first and 69 % in the second assay after treatment with the highest test concentration of 10000 μg/ml medium.
Thus, the NRU-50 was > 10000 μg/ml.
The NRU-50 values obtained with the positive control SLS (12.5 and 15.6 μg/ml) were in the range of the historical control data of the laboratory and demonstrate the validity and sensitivity of the assay.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Not eye irritant

Executive summary:

According to the classification system of the performing laboratory discriminating between non irritant, not-classified and severe, the tested substance is classified as non-irritant.