Enhancement effect of ethanol/panasate 800 binary vehicle on skin permeation of alclofenac

The in vitro skin permeation using hairless mouse and in vivo skin absorption using rat of alclofenac from ethanol/panasate 800 (tricaprylin) binary vehicle were investigated. The in vitro skin permeability of alclofenac was remarkably enhanced by the combination of ethanol and panasate 800. The greatest enhancement was obtained in the ethanol/panasate 800 (40/60) system. The results of in vivo skin absorption of alclofenac were shown almost the same tendency as that of the in vitro permeation. The skin permeation enhancement mechanism of alclofenac from the ethanol/panasate 800 (40/60) binary vehicle was evaluated by clarifying the different behavior of ethanol and panasate 800 for the diffusion process in the skin. It is suggested that ethanol increases permeation flux by increasing the uptake of alclofenac in the skin tissue and by gradually reducing the barrier function of stratum corneum. On the other hand, panasate 800 reduces lag time by increasing the uptake rate and diffusion of alclofenac in the stratum corneum and viable skin. Therefore, the enhancement effect of the ethanol/panasate 800 (40/60)binary vehicle is considered to be due to the mutual effect which is obtained by the effective interaction of the two vehicles.