ABSTRACT
Although tests using animals are still demanded in the evaluation fo shampoos, there is a strong evidence of a tendency for replacing them by in vitro systems. This study aims at defining conditions for the application of a method using NCTC clone 929 cells, as an alternative. Procedures employed to test non diluted samples of shampoos for adults resulted in irritation (in the in vivo method); the same result was not observed when samplesdiluted to a 25 per cent concentration were tested. In the in vitro tests, the same shampoos presented a perfect correlation of results when not diluted (cytotoxic) and when diluted to a 0.1 per cent concentration (non cytotoxic). When the shampoos for children use were tested, the only case of irritation happened with one of the 4 non-diluted shampoos. The absence of cytotoxicity was observed in the in vitro test, after diluting all the samples to 1 per cent and 0.1 per cent. It is possible thus to use the in vitro test instead of the vivo one, if preceded by a careful validation with emphasis on the concentration of the product