Design and Release Kinetic Studies of Nimesulide Bioadhesive Topical Gel

Abstract

The objective of the present investigation was to develop topical gel of nimesulide using model polymers such as hydroxypropyl methylcellulose K100M (HPMC K100M) and carbopol 940 at different concentrations individually and in combination. The drug and polymers compatibility study was carried out by FTIR technique. The gels were evaluated for drug content, viscosity, pH, homogenecity, spreadability and in-vitro drug release. The FTIR spectra of drug alone and in physical mixture with polymers did not show any shift in major peaks, which indicates no drug-polymer interaction. All the data obtained from above physicochemical parameters were satisfactory. In-vitro drug release of gels was performed using Franz diffusion cell with cellulose acetate membrane in phosphate buffer pH 7.4 as receptor medium. According to the release study, the drug release was decreasing with the increasing polymer concentration in each formulation. The correlation coefficient (R2) values demonstrate that the drug release pattern followed Higuchi model except BTG2 and BTG4. The release exponent (n) values were within 0.78 to 0.98 for all formulations. The above results showed that swelling and diffusion (Non-Fickian diffusion) were the drug release mechanism.