DEVELOPMENT OF AN IN VITRO METHOD FOR SKIN CORROSION TESTING.

Scientists from The Procter and Gamble Company investigated the feasibility of an in-vitro skin corrosion test method using commercially available human skin cultures. Skin2 from Advanced Tissue Sciences and EpiDerm from MatTek were evaluated for their responses to 24 corrosive and non-corrosive materials. The multilayered epidermis of the Skin2 cultures contained a basal layer of keratinocytes, a stratum corneum and a stromal component. The EpiDerm cultures did not have a dermal element, but had a stratified and cornified epithelium. Epithelial degradation and necrosis were graded on a scale of 0 to 5 after exposure to the test materials. Plastic embedding as opposed to paraffin embedding of Skin2 cultures gave results comparable to those of EpiDerm cultures. Treatment of both cultures with corrosive materials produced significantly severe histological changes in under 3 minutes (min). Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide (MTT) vital dye metabolism and found to be consistent for both skin cultures. A 50% reduction in cell viability, designated the t50 value, after less than a 3 min. exposure to the test substances was used to classify materials as corrosives. This method was used to evaluate nine corrosive chemicals and 15 skin irritants. The MTT assay results correlated with the histological grading of corrosive effects. The authors conclude that use of human skin cultures in corrosive evaluation provides a reliable replacement for the use of in-vivo animal testing.

Animal testing, Cell viability, Corrosion, Corrosivity, Corrosivity testing, Dermal corrosion, EpiDerm, Epithelial, Epithelial degradation, MTT, MTT ET-50 tissue viability assay, MTT assay, Necrosis, Skin corrosion, Skin corrosivity