Topical Application of Penetration Enhancers to the Skin of Nude Mice: a Histopathological Study

Abstract
Eighteen potential penetration enhancers, some at concentrations that might be used for that purpose, have been examined to evaluate their irritancy potential on nude mouse skin. A biopsy technique was employed followed by histological examination. Up to 50% glycerol, 10% hydroxyethyl lactamide (HELA), 10% oleyl alcohol, 10% Solketal, 10% glycofurol, 100% tetrahydrofurfuryl alcohol (THFA) and 10% urea induced no discernible change in the histological appearance of the skin whereas 100% dimethyl sulphoxide (DMSO), 100% dimethyl formamide (DMF), 100% N-methyl-2-pyrrolidone, 10% Azone, 10% oleic acid, 10% methyl laurate, 10% benzyl alcohol and 10% glycerol formal caused severe skin irritation.