Skin irritancy classification of body cleansing products: Comparison of two test methodologies.

Abstract

Mildness of skin cleansing products is often claimed although difficult to substantiate. Both the society and the producer share a common interest that cleansing products are safe in use and that valid methods are used for premarketing evaluation of new products. The object of the present study was to evaluate methodological aspects when three products were compared using two different test systems to characterize their irritant properties. A modified soap chamber test (M-SCT) and an iterative short-term patch test (IPT) were performed. Eight healthy female volunteers aged 18 to 55 selected as having responsive skin were studied. Colorimetry and measurement of transepider-mal water loss was employed. A soap, a synthetic detergent bar and a facial cleanser were studied with deionized water as a reference. The IPT appeared more sensitive than the M-SCT for the detection and discrimination of irritation. The techniques allowed the ranking of the irritant properties of the products relative to water, which showed low values in both systems. Ranking of irritant properties of cleansing products was possible even in a limited number of individuals. Iterative short-term patch test was more sensitive than a modified soap chamber test.