Applications of the EYTEX™ method

The EYTEX™ method is an in vitro test to predict the ocular irritation of chemicals and formulations based on alterations in a protein matrix. Results of a multi-laboratory study of 130 samples have previously been published. Four independent studies were conducted to evaluate further the accuracy, reproducibility and applicability of the EYTEX™ method. This method was performed according to the previously published procedures. Dose-response curves were produced at concentrations of samples similar to those used in the Draize test. Spectrophotometric data were used to establish irritancy classifications, and an EYTEX™/Draize equivalent was calculated. These studies included a wide range of chemicals and formulations with varying degrees of irritation and mechanisms of ocular toxicity. Nine hundred and twenty-one cosmetic, household, petroleum and agricultural products were analysed by the EYTEX™ method. Seven hundred and thirty-six EYTEX™ results were within one classification of the Draize result. The EYTEX™ results exhibited an overall substantial equivalence of 91% to the Draize results with a range of 89 to 93% depending on the particular product group. The inter-assay coefficient of variation was 8.1% and the intra-assay coefficient of variation was 10.7%. These studies indicate that the EYTEX™ method exhibits a high correlation with the Draize test for the four diverse product groups studied and validates the predictive potential of the EYTEX™ method as an in vitro screen for ocular irritation.