Advances in topical corticosteroid therapy

Many skin preparations are used by the dermatologist, a large proportion being based on corticosteroids. The relationship between the chemical structure of twenty corticosteroids and their ability to permeate freshly excised hairless mouse skin was studied. It was found that increasing the 17-carbon side chain, including a fluoro at carbon 9, and the addition of 10% w/v urea, diethyltoluamide or diethylbenzamide to the vehicle all increased skin penetration. Of the twenty compounds studied, seventeen were new, and as yet unreported. The present studies were also initiated to answer questions about the usefulness of the hairless mouse for developing clinically relevant insights into percutaneous absorption and for evaluating topical products intended for humans.