FORMULATION AND EVALUATION OF CERTAIN ANTI-INFLAMMATORY DRUGS FOR TOPICAL APPLICATION. 1- OINTMENT FORMS

Document Type : Original Article

Authors

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

Abstract

The influence of type of vehicle on the in-vitro and anti-inflammatory effect of flufenamic and mefenamic acids has been studied. The vehicle investigated consisted of: water soluble base, an absorption base and two emulsion bases (O/W and W/O).
In-vitro release was evaluated using a diffusion assembly fitted with Fischer cellulose membrane (30/32) as diffusion barrier. Phosphate buffer of pH 6.8 at 35° C (±2) was used as release medium.
The results revealed that, the rate and amount of drug released was greatly affected by the type of base and nature of drug. The ointment bases can be arranged according to in-vitro release for both flufenamic and mefenamic acids as follows: water-soluble base > water-in oil emulsion base > oil in-water emulsion base > absorption base. Anti-inflammatory effect was studied on inflamed tissue of albino rabbit. The selected ointment bases were uniformly spread over the shaved inflamed back skin of rabbit for several days. The ointment bases can be arranged in descending order according to anti-inflammatory effect after topical application to inflamed tissue as follows: Absorption base > water in-oil emulsion base > oil-in-water emulsion base> water soluble base. Trials to find out any correlation between in-vitro release and anti-inflammatory effect for both flufenamic and mefenamic acids were carried out. It was found that there is only correlation between in-vitro release and anti-inflammatory effect for emulsion base (W/O, O/W) for both flufenamic and mefenamic acids.