A lamellar matrix model for stratum corneum intercellular lipids IV. Effects of terpene penetration enhancers on the permeation of 5-fluorouracil and oestradiol through the matrix

Abstract

It is widely accepted that the intercellular lipid domain of the stratum corneum (SC) is the main barrier to transdermal permeation of most drugs. Previously, we reported a lamellar lipid matrix capable of modelling 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, permeation of model drugs (OE and 5-FU) through cineole or limonene treated matrices were investigated here. Results revealed that the matrix is able to model the effects of cineole and limonene on the permeability coefficients of OE through the SC. The effects of cineole on the permeability coefficient of 5-FU through the SC seem to be underestimated by the model matrix; the difference was attributed to the effects of cineole on the SC intracellular proteins or to differences in the hydrophilicities of the SC lipids and the matrix. The matrix failed to model the enhancement effect of limonene toward permeation of 5-FU through the SC which might indicate that limonene increases the permeation of 5-FU in part through interactions with SC proteins which are not modelled in the matrix.