FORMULATION AND EVALUATION OF CERTAIN ANTI-INFLAMMATORY DRUGS FOR TOPICAL APPLICATION. II: POLYMER FILM FORMS

Document Type : Original Article

Authors

Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

The release characteristics of the nonsteroidal anti-inflammatory drugs, flufenamic and mefenamic acids from ethyl cellulose and polyvinylacetate polymeric cast films were studied.
The effect of formulation variables of the films composition viz. nonionic surfactants (Tween 80 and Span 20), and additive polymer (polypropylene glycol 2000 and polyethylene glycol 400) on the release characteristics of both drugs were also investigated. The effect of addition of hydroxypropylcellulose in different ratios to polyvinylacetate films at constant flufenamic acid concentration, on the release characteristics of the drug was also evaluated.
Further, the permeability properties of both free polymeric films for both drugs was evaluated and correlated with drug penetration through the skin of the rat, on the basis of the permeability constant and diffusion coefficient. Kinetic data analysis proved that the mechanism of release of both drugs followed a diffusion controlled model from the two polymeric films.
The release rate in pure and in mixed films was increased by Tween 80 or polyethylene glycol 400. Also release rate of flufenamic acid was increased markedly by inclusion of hydroxypropyl cellulose to polyvinylacetate film to certain extent. Flufenamic acid release rate was always higher than that of mefenamic acid from both polymers. It was found that flufenamic acid had the higher diffusion coefficient than that of mefenamic acid.