Kinetic study of the percutaneous absorption of 1,2,4-3H-labelled flupamesone

Abstract

Two different creams containing 4,4'-methylene bis-[(9 alpha-fluor-11 beta,21-dihydroxy-16alpha,17alpha-isopropylidenedioxy-1,4-pregnadiene-3,20-dione)-3-methoxy-2-naphthoate] (flupamesone) and triamcinolone-acetonide, both labelled with tritium, were prepared in order to study their absorption kinetics. Results were compared in order to find structure-activity relations following Malkinson's hypothesis. The radioactivity was measured in samples of skin taken at various intervals of time after the application of the cream. The results showed a reservoir of corticoids at 400--700 mu depth and that flupamesone remains longer in skin than does triamcinolone-acetonide.