Investigation of ingredient interactions in cosmetic formulations using isolated bovine corneas.

The purpose of this paper is to report on use of a modified bovine cornea opacity and permeability assay (BCOP) to test the effects of several cosmetic formulations on eye-derived tissue in vitro. The results from these studies suggest that a BCOP protocol using prolonged exposure and repeated treatments may be useful for screening the eye effects of cosmetic formulations. Further work will be required, however, before the model is ready for formal validation. This series of experiments also provides an example of where the toxicity of one ingredient was significantly changed by its interaction with other ingredients in a mixture. As it was not possible to predict the highly reactive nature of the formulation in vitro based on an evaluation of ingredient toxicity data alone, this case illustrates the importance of obtaining adequate safety testing data on innovative mixtures of cosmetic ingredients before human exposure is allowed.