Abstract

The aim of this study was to develop a new extended release capsules of indomethacin. The formulation has been prepared to enhance its dissolution which could provide better oral absorption of indomethacin (IND). Therefore, the effects of the component nature, their proportion in the release rate and the dissolution mechanism were investigated. Extended release capsules of IND were prepared by physical mixing using plasdone (PVP K-90) and compritol-HD5 ATO (Comp) at various drug-polymer ratios. Flow properties of the physical mixtures were evaluated by calculation of the Carr’s index, angle of repose and Hausner ratio. According to the United States Pharmacopeial (USP) drug release criteria of IND extend release capsules, the release results of formulations F2 and F3 were found to be similar to the USP (P < 0.05). Certain mathematical models were used for evaluation of release profiles and the results supported by multiple regression analysis. It was observed that the best-fit model to determine the mechanism of the formulation which has shown the highest release was Higuchi square-root of time model (r² = 0.969). According to the dissolution results, dissolution efficiency, relative dissolution rate and mean dissolution time were also evaluated. The results of the study indicated that new extended release hard gelatin capsules can be a promising alternative for the other oral formulations of IND.

Key words: Indomethacin, drug release, kinetic evaluation, hard gelatine capsule, stability, multiple regression analysis.