Effect of permeation enhancers on the in vitro percutaneous absorption of pentazocine

The effect of permeation enhancers on the percutaneous absorption of pentazoeine (PTZ) was investigated in excised hairless mice using Franz diffusion cells in vitro. The enhancing effect on the percutaneous absorption of PTZ from the isopropyl myristate (IPM) solution system was improved with glyceryl monocaprylate (GEFA-C-8), which is a kind of glycerol ester of fatty acid (GEFA). The flux of PTZ through the skin was ca. 4 times higher compared with IPM alone, while a less enhancing effect of glyceryl dicaprylate (GEFA-DiC(8)) and glyceryl tricaprylate (GEFA-TriC(8)) on the skin permeation of PTZ was found. Moreover, maximum enhancement of PTZ flux was observed with glyceryl monocaproate (GEFA-C-6) among various alkyl chains (C-2-C-18) of monoglyc- erides. These results indicated that the IPM solution system combination with GEFA may be used to develop a transdermal formulation with improved skin permeation of PTZ.