PHARMACOTOXICOLOGICAL APPLICATIONS OF AN EQUIVALENT DERMIS - 3 MEASUREMENTS OF CYTOTOXICITY

The legal procedure for evaluating the toxicity of cosmetic, household , chemical and pharmaceutical products is still the irritancy Draize t est on rabbits. Various irritation tests are currently being developed as alternatives to in vivo animal testing. Our in vitro model system is composed of 24 equivalent dermis (ED) comprising a chitosan-cross-l inked collagen-glycosaminoglycan matrix populated by foreskin fibrobla sts. In evaluating this system for irritancy testing, three different measures of toxicity were used: MTT (dimethylthiazol diphenyltetrazoli um bromide) reduction, and lactate dehydrogenase and interleukin-ti re lease. The experiments described herein represent a preliminary evalua tion to determine the usefulness and predictive value of our 24 ED kit as an alternative method for the prediction of human dermal reaction, versus three chemical products: cadmium chloride, lauryl sulfate, and benzalkonium chloride. Preliminary results suggest that the ED may be a useful in vitro model for the prediction of cutaneous and ocular to xicity and allow the development of a 24-skin-equivalent kit realized by seeding human normal keratinocytes onto the equivalent dermis.