Use of a standardized reconstructed epidermis kit to assess in vitro the tolerance and the efficacy of cosmetics.

The development and validation of alternative methods to animal testing is one of the major priorities for the cosmetic industry. These methods must be reproducible and predictive of the effect of cosmetics during normal use by the consumer. Among alternative methods recently proposed, those using reconstructed human epidermis kits are the most promising approach for this purpose, as these models mimic the site of product application, allow topical application and the assessment of some clinical reactions. However, the realistic use of these models requires reproducibility and relevance of the results. The achievement of these conditions could allow the evaluation of large amounts of products, their comparisons and the generation of data banks on finished products and their ingredients. Only kits manufactured on an industrial scale and in stringent conditions of quality assurance can meet these requirements. As an example, both the criteria for industrial scale usage and the results of reproducibility of results obtained over a 4-year period (135 batches) are reported here, in terms of histological and biochemical criteria (generally used to assess the efficacy or tolerance), for a reconstructed human epidermis elaborated as a kit, EPISKIN(R). These results may provide the framework for a validation and recognition of the model, within guidelines for the assessment of the efficacy and tolerance of cosmetics.