Transdermal delivery of ketoprofen using microemulsions

A transdermal preparation containing ketoprofen was developed using O/W mic roemulsion system. Of the oils tested, oleic acid was chosen as the oil pha se of the microemulsion, as it showed a good solubilizing capacity and exce llent skin permeation rate of the drug. Pseudoternary phase diagrams were c onstructed to obtain the concentration range of oil, surfactant and cosurfa ctant for microemulsion formation, and the effect or these additives on ski n permeation of ketoprofen was evaluated with excised rat skins. The optimu m formulation of the microemulsion consisted of 3% ketoprofen, 6% oleic aci d, 30% Labrasol/Cremophor RH 40 (1:1) and water. Terpenes were added to the microemulsion at the level of 5% and their effect on the skin permeation o f ketoprofen from the microemulsion was evaluated. Of the four terpenes use d, only limonene resulted in a powerful enhancing activity (3-fold increase over control). (C) 2001 Elsevier Science B.V. All rights reserved.