Enhancement of ketorolac tromethamine permeability through rat skin using penetration enhancers: An ex-vivo study

Introduction: Ketorolac tromethamine (KT), a nonsteroidal anti-infl ammatory drug, when given orally causes gastrointestinal disturbances. Its transdermal drug delivery may reduce such side effects associated with them. The present investigation was aimed at evaluating the effi ciency of various penetration enhancers for improved permeation of KT through the skin. Materials and Methods: A concentration of 1 mg/mL of the drug solution with enhancers was used to evaluate diffusion through the rat skin using a Franz diffusion cell assembly. 20 different penetration enhancers were selected for this study. Results: Saturated fatty acids like stearic and palmitic acid were found to increase the permeation rate of the drug to a great extent whereas unsaturated fatty acid viz. oleic acid exhibited maximum permeation. Increase in permeability effi ciency of various penetration enhancers was observed in the following order: Oleic acid > stearic acid > palmitic acid > isopropyl myristate > tween 80 > span 80 > span 40 > span 20 > l-limonene > l-menthol > fenchone > α-pinene > urea > dimethyl sulfoxide (DMSO) > triton X-100 > tween 20 > dimethyl formamide > acetone > control > citric acid > ascorbic acid. Ascorbic acid and citric acid had no effect on permeation rate. Conclusion: The results revealed that the permeation of KT through the skin can maximally be enhanced using oleic acid-an unsaturated fatty acid.