In vitro release studies of methyl salicylate from the ointment bases and the commercial dermatological products.

Methyl salicylate, a lipophilic liquid is one of the most commonly used analgesic, counterirritant and rubifacient ingredients in the commercially marketed over-the-counter dermatological products. And, since the effectiveness of the topically applied product depends on the release of the drug from such a dosage form, the present study was proposed to investigate the in vitro release of methyl salicylate from the typical ointment bases and several commercial products. Also, the effects of various additive ingredients on the drug release from these bases were evaluated. In general, the selected ointment bases gave superior in vitro drug release profiles compared to all commercial products included in this study. The addition of ethanol at 10% level in these ointment bases significantly enhanced the drug release from the selected formulations.