THE INFLUENCE OF ETHANOL ON PERMEATION BEHAVIOR OF THE POROUS PATHWAYIN THE STRATUM-CORNEUM

Relationship between in vitro percutaneous penetration of baclofen, a model zwitterion, and ethanol concentration in the vehicle was studied . In comparison with water, 95% ethanol increases the permeability coe fficient of baclofen by a factor of 10, which suggests rapid and maxim al pore formation in the stratum corneum. A slow time-dependent increa se of penetration rate was observed for lower ethanol concentrations. For ethanol concentrations in the range 0-70%, solubility of baclofen in the vehicle is a dominant factor influencing the penetration rate. The reasons for an unexpectedly small effect of 70% ethanol on the pro cess of pore formation in the stratum corneum are discussed.