In order to reduce the systemic side effects and gastrointestinal irritation of ketoprofen after its oral administration, it was formulated as a 3% ketoprofen gel (ID-GEL) with Pluronic F-127. The pharmacokinetic characteristics of ID-GEL was evaluated following its transdermal application on the dorsal skin of rats at the dose of 9 mg/kg in reference to those of existing 3% ketoprofen gels. Even though the maximum concentration of 810 ng/ml was reached at 6 hrs postdose, the plasma concentration was kept almost constant until 24 hrs postdose, which suggested that ketoprofen was released continuously from the gel during this period. The bioavailability of ID-GEL was two times higher than those of existing 3% ketoprofen gels, based on the calculated area under the plasma concentration-time curves after the percutaneous administration.