Comparative study of the efficacy of various moisturizers on the skin of the ASR miniature swine

The skin of the back of the ASR hairless miniature swine shows a rough and scaly fissured appearance. Clinically it resembles that of ichthyosis vulga ris or senile xerosis in humans. By using the skin of this animal, we devel oped an assay system to evaluate the efficacy of different moisturizers. Th e study was carried out in winter months from January to March. To establis h this system, we studied various topical agents including such ordinary em ollients as petrolatum and 10% salicylic acid in petrolatum as well as thos e available as pseudodrugs from cosmetic companies or prescription drugs fr om pharmaceutical companies such as heparinoid-containing creams (w/o and o /w) and 10% urea creams. Applying 0.01 g of each agent to 7 randomly select ed skin areas (2 x 2 cm(2)) on the back of a 6-month-old swine once daily f or various periods of time, we measured high-frequency conductance, the par ameter for the hydration state of the skin surface. As a result, we have es tablished a simple assay system. It consists of applications of topical age nts once daily for 5 days from Monday to Friday in the first week and of su bsequent measurement of the skin surface hydration state once every week. E valuation measurements were performed from day 14 to day 21 depending upon their moisturizing effects. We found that heparinoid-containing creams exer ted highly effective moisturizing effects on the dry pig skin that lasted e ven over 3 weeks after discontinuation of the treatments that were carried out for the first 5 days. Copyright (C) 2000 S.Karger AG, Basel.