Effect of chemical enhancers on the in vitro percutaneous absorption of sumatriptan succinate

The effects of percutaneous enhancers on the transdermal absorption of sumatriptan succinate were investigated by in vitro permeation studies. Pretreatment of porcine skin with ethanol (vehicle), polyethylene glycol 600, Span® 20, oleic acid, R-(+)-limonene, α-bisabolol and 1,8-cineole (at 5% in ethanol, w/w) produced in all cases an increase in the flux of sumatriptan. The amount of sumatriptan retained in the skin was also determined. Ethanol has showed a low but significant increment on the drug transdermal flux. Treatment of the skin with α-bisabolol shows the same enhancer effect than ethanol. Span® 20, oleic acid, and polyethylene glycol 600 have shown a moderate enhancing activity on transdermal flux of sumatriptan. R-(+)-limonene showed the greatest ability to enhance the flux of sumatriptan.