HII mesophase as a drug delivery system for topical application of methyl salicylate

The main objective of this study was to develop reversed hexagonal (H II ) mesophase for transdermal delivery of methyl salicylate . The formulation was prepared, characterized and evaluated for its skin penetration in vitro and skin retention in vivo. Preliminary pharmacodynamics and skin irritation were also investigated. The formulation was identified as hexagonal structure. In vitro study exhibited that H II mesophase enhanced the skin permeation by delivering 2.61 times more methyl salicylate than the commercially available cream. Meanwhile, H II mesophase presented higher bioavailability as AUC (0–24) and AUC (0–∞) were 32.894   μg·mL −   1 and 32.935   μg·mL −   1 respectively, while the cream were 12.791   μg·mL −   1 and 12.970   μg·mL −   1 . Preliminary pharmacodynamics studies demonstrated that H II mesophase possessed anti-inflammatory and analgesic effects for inhibiting paw edema , granuloma and pain. MeSa H II mesophase showed no skin irritation on the normal rat skin. Thus, H II mesophase was considered as an effective delivery system for MeSa.