The objective of this study was to determine the effect of naturally occurring terpenes on the skin permeation of rofecoxib from the transdermal gel prepared with Sodium alginate-Carbopol 940 for topical application. Using invitro techniques, three different types of naturally occurring terpenes (α-terpineol, + limonene and camphor) were evaluated for the skin permeation of rofecoxib from gel formulations. The effect of concentration of terpenes on the rate of drug permeation from the gel formulations were examined through rat skin mounting on a Keshary-Chien diffusion cell. All the terpenes showed good permeation of rofecoxib from gel formulations. However, α-terpineol at 3% w/w was more effective enhancer with enhancement ratios up to three fold compared with the formulation without terpenes, where as the camphor was much less efficient. The physicochemical properties of the prepared gel formulations were in good agreement with those of a marketed product, indicating feasibility of the topical gel formulation of rofecoxib.
