EVALUATION OF A 3-DIMENSIONAL HUMAN DERMAL MODEL AS A PREDICTOR OF SHAMPOO OCULAR IRRITATION

A three-dimensional human tissue model (Skin(2) ZK1100) was used, to e valuate 43 adult and baby shampoos. The ZK1100 model consists of metab olically active proliferating human fibroblasts isolated from the derm is of neonatal foreskins and seeded onto a nylon mesh. The fibroblasts multiply and produce matrix proteins to form a living tissue. MTT red uction (mitochondrial function) was used as the cytotoxicity endpoint. The primary components of the adult shampoos are alkyl sulfate surfac tants, while the baby shampoos contain ethoxylated alkyl sulfates and amphoteric surfactants. All shampoos were diluted to five concentratio ns (100, 300, 700, 1000 and 3000 mu g/ml) in aqueous cell culture medi a and the tissue exposed for 24 hr. An EC(50) value for each test was generated from a dose-response curve. All samples were tested in two o r more separate experiments, and the EC(50) values were averaged and p lotted versus their respective 24-hr unwashed Draize eye irritation va lues (r(2) = 0.81). The adult shampoos had Draize values in the modera te irritation category and EC(50) values ranging from 220 to 1051 mu g /ml, while the baby shampoos had Draize values in the minimal irritati on category and EC(50) values ranging from 820 to 2285 mu g/ml. These results indicate that the three-dimensional human tissue model can be useful in predicting the Draize ocular irritation