A lamellar matrix model for stratum corneum intercellular lipids III. Effects of terpene penetration enhancers on the release of 5-fluorouracil and oestradiol from the matrix

Abstract

Previously, we reported a lamellar lipid matrix capable of modelling the structural and barrier properties of the stratum corneum (SC) intercellular lipids and that oestradiol (OE) and 5-fluorouracil (5-FU) permeate the SC through intercellular channels. To investigate the ability of the matrix in modelling the effects of terpene penetration enhancers on the diffusion of OE and 5-FU through the SC, release of these drugs from cineole or limonene treated matrices were studied here. Results revealed that the matrix is able to model the effects of cineole and limonene on the diffusion coefficient of OE and the effect of cineole on the diffusivity of 5-FU through the SC. The matrix failed to model the enhancement effect of limonene toward diffusion 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. The effects of temperature on the enhancement efficiency of cineole toward diffusion of 5-FU through the matrix were investigated and results revealed that when the matrix lamellar structure is disrupted by temperature, little potential is left for further disruption and, therefore, penetration enhancement by cineole, is in good agreement with human epidermis data.