Interlaboratory validation of the in vitro eye irritation tests for cosmetic ingredients. (11) EYTEX(TM)

EYTEX(TM) is an in vitro test system for predicting the ocular irritation potential of chemicals and formulations. This method was evaluated as an alternative method to the Draize eye irritation test (Draize test) for the eye irritation potential of several cosmetic ingredients in a three-phase validation study conducted at five to seven laboratories. Thirty-nine test substances were used as coded samples. The test procedures were controlled under the same standard operating procedure (SOP) at all participating laboratories. The interlaboratory coefficient of variation (CV) was 20.8%. The correlation coefficient between EYTEX scores and the maximal average Draize total score (MAS) was 0.313. Irritancy classifications were established based on the results of 54 EYTEX tests and the EYTEX/Draize equivalent was calculated. Thirty-eight EYTEX test results concurred with the results of the Draize test, substantial equivalence was 70.4%. These results indicate that EYTEX provides a rough method of classification rather than providing absolute values. The present results also indicate that EYTEX has the following characteristics: (1) intensely coloured substance may not be compatible; (2) some cationic surfactants may be underestimated; (3) EYTEX can be applied to most test substances under the same conditions as the in vivo tests.