Enhancement of percutaneous absorption of ketoprofen: effect of vehicles and adhesive matrix

The effects of various vehicles on percutaneous absorption of ketoprofen in a solution formulation and in a pressure-sensitive adhesive (PSA) matrix were evaluated. The permeation rate of ketoprofen across hairless mouse skin was evaluated using a flow-through diffusion cell system at 37 degrees C. The solubility of ketoprofen was determined using the equilibrium solubility method. Among tested vehicles, octanol, ethanol, and propylene glycol (PG)/oleyl alcohol (OA) mixture showed the highest flux of 30 mu g/cm(2) per h from 5 mg/ml solution. However, it was not possible to demonstrate any correlation between the solubility of ketoprofen and its permeation rate, indicating change in the barrier property of the skin and/or carrier mechanism by vehicles used. When the effects of various vehicles on the percutaneous absorption of ketoprofen from acrylic PSA matrix were evaluated, oleic acid showed a slightly higher flux of 2 mu g/cm(2) per h than all other solvents tested. As the concentration of ketoprofen in acrylic PSA matrix increased from 6.3 to 16.7%, the permeation rate also increased almost linearly. The permeation rate of ketoprofen from polyisobutylene (PIB)-type PSA matrix was more than three times higher than that from acrylic PSA matrix. (C) 1998 Elsevier Science B.V. All rights reserved.