Regular Article :AATEX 3(4):199-209
The EYTEXR method was evaluated in five laboratories as an alternative method to predict the eye irritation of cosmetic ingredients. Nine surfactants and Isotonic Sodium Chloride Solution were evaluated as coded samples. Two of the nine surfactant samples studied. Sodium Hydrogenated Tallow-L-glutamate and Polyoxyethylene Octylphenylether (10 E.O.), were found to suppress or inhibit the EYTEXR reaction system so that the test results obtained with these samples were invalid and had a low degree of correlation with the in vivo study results. However, the test results for the remaining 8 samples were valid, showing a small degree of interlaboratory variation (the coefficient of variation: 25%, or less). A high correlation coefficient was obtained between the scores for the eight samples obtained by the EYTEXR method and those from the in vivo test method. The correlation coefficient was high in particular in comparison to the evaluation of conjunctival reactions, 0.884 for the maximum score, 0.955 for the 24th score and 0.767 for the area under the curve (AUC). The corresponding values for maximal average total Draize score (BIAS) were 0.710, 0.703, and 0.657, respectively. The irritation ranking for the eight samples, excluding for the above-mentioned two samples, as determined by the EYTEXR method corresponded with those obtained by the in vivo test.
Even though two substances were not compatible with The EYTEXR method, we concluded that EYTEXR is a promising alternative method to the Draize eye irritation test (Draize test) based on the results obtained for the remaining 8 samples and the relatively simple assay procedure. Further validation of this method using a wider range of cosmetic ingredients is under way.
Key words: EYTEXR, validation study, Draize eye irritation test, , alternatives, surfactant, in vitro.