Application of the EYTEX system to the evaluation of cosmetic products and their ingredients

By Kruszewski, F.H. - Hearn, L.H. - Smith, K.T. - Teal, J.J. - Gordon, V.C. - Dickens, M.S.

465 cosmetic product formulations and raw ingredients were evaluated with the EYTEX system to determine the potential of this in vitro alternative for identifying eye irritation potential. The EYTEX system is non-animal, biochemical procedure developed by Ropak Laboratories, Irvine, CA, that was designed to approximate the Draize rabbit eve irritation assay for the evaluation of ocular irritation. Avon Products Inc. provided all the test samples, which included over 30 different product types and represented a wide range of eye irritancy. All the EYTEX protocols available at the time of this study were used. Samples were evaluated double-blind with both the membrane partition assay (MPA) and the rapid membrane assay (RMA). When appropriate, the standard assay (STD) and the alkaline membrane assay (AMA) were used, as well as specific, documented protocol modifications. EYTEX results were correlated with rabbit eye irritation data which was obtained from the historical records of Avon Products Inc. A positive agreement of EYTEX results with the in vivo assay was demonstrated by an overall concordance of 80%. The assay error was 20%, of which 18% was due to an overestimation of sample irritancy (false positives) and 2%, was attributed to underestimation (false negatives). Overestimation error in this study was due in part to the inability of the protocols to accurately classify test samples with very low irritation potential. Underestimation of sample irritancy was generally associated with ethoxylated materials and high concentrations of specific types of surfactants. 100% sensitivity and 85% predictability were described by the data, indicating the efficiency of EYTEX in identifying known irritants. A specificity rate of 39% showed the EYTEX assay to be weak in discerning non-irritants. However, the EYTEX protocols used in this study were not designed to identify non-irritants. A compatibility rate of 99% proved the effectiveness of the EYTEX assay in accommodating a diversity of product types. The EYTEX system protocols, when used appropriately, can provide a conservative means of assessing the irritant potential of most cosmetic formulations and their ingredients.