Abstract:
A unique transdermal drug delivery system of ketoprofen was developed in this study. To enhance the permeation of ketoprofen, four permeation enhancers were studied: carvacrol, cineole, limonene and Panasate 800. The solubility of ketoprofen in various vehicles consisting of ethanol (EtOH), propylene glycol (PG) and water (W) in various proportions and in the presence of these enhancers was determined. In
vitro skin permeation of ketoprofen in the various formulae as well as a commercial gel were investigated using human epidermis. The concentration of ketoprofen used was at its saturation point and at 16.5 mg/mL. 2% limonene in vehicle 60:30:10 clearly gave the best flux of 476.0 μg/cm2/hr. The second best formula was 40% Panasate 800 in EtOH which gave the flux of 84.0 μg/cm2/hr. When the
concentration was increased to 165 mg/mL, the flux of 40% Panasate 800 in EtOH increased to 399.9 μg/cm2/hr, a value slightly higher than the theoretical flux of 346.5 μg/cm2/hr. In studying the effect of the controlling membrane (9% ethylene vinyl acetate) on the flux of 40% Panasate 800 in EtOH, the flux declined to 2.8 μg/cm2/hr, while the membrane became the rate-limiting step. An evaluation of stability showed that 4% carvacrol in vehicle EtOH:PG:W 30:30:40 and that 1% limonene in vehicle EtOH:PG:W 40:30:30 were, respectively, not physically and not chemically stable. Other formulae, however, were both physically and chemically stable after a 90-day storage at room temperature. Compared with a commercial gel, 40% Panasate 800 in EtOH with an equal concentration of ketoprofen showed a significantly higher permeation