Role of volatile oil pretreatment and skin cholesterol on permeation of ion-paired diclofenac sodium.

ABSTRACT

This study was designed to investigate the influence of volatile oil pretreated skin on in vitro permeation from films containing ionized and dodecylamine ion-paired diclofenac sodium (DS). The involvement of skin cholesterol was investigated to determine its possible role in enhancing the permeation of ion-paired DS. Cardamom oil produced the maximum (10 x) in vitro permeation enhancement for ion-paired DS. The carrageenan induced rat paw oedema reduction (up to 12 hr) by cardamom oil was comparable to that of diclofenac injection (s c). Leaching of cholesterol from excised skin in addition to increased partition coefficient following volatile oil skin pretreatment appears to be responsible for in vitro permeation enhancement of DS. Whereas, a mild barrier perturbation effect due to altered cholesterol levels following pretreatment with volatile oils appears to increase the permeation of ion-paired DS across viable skin, thereby producing significant reduction of carrageenan induced paw oedema.