A LAMELLAR MATRIX MODEL FOR STRATUM-CORNEUM INTERCELLULAR LIPIDS .4. EFFECTS OF TERPENE PENETRATION ENHANCERS ON THE PERMEATION OF 5-FLUOROURACIL AND ESTRADIOL THROUGH THE MATRIX

It is widely accepted that the intercellular lipid domain of the strat um corneum (SC) is the main barrier to transdermal permeation of most drugs. Previously, we reported a lamellar lipid matrix capable of mode lling the structural properties of the SC intercellular lipids and its barrier performance toward oestradiol (OE) and 5-fluorouracil (5-FU). To investigate the ability of the matrix in modelling the effects of terpene penetration enhancers on the barrier performance of the SC, pe rmeation of model drugs (OE and 5-FU) through cineole or limonene trea ted matrices were investigated here. Results revealed that the matrix is able to model the effects of cineole and limonene on the permeabili ty coefficients of OE through the SC. The effects of cineole on the pe rmeability coefficient of 5-FU through the SC seem to be underestimate d by the model matrix; the difference was attributed to the effects of cineole on the SC intracellular proteins or to differences in the hyd rophilicities of the SC lipids and the matrix. The matrix failed to mo del the enhancement effect of limonene toward permeation of 5-FU throu gh the SC which might indicate that limonene increases the permeation of 5-FU in part through interactions with SC proteins which are not mo delled in the matrix. Copyright (C) 1996 Elsevier Science B.V.