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Formulation and evaluation of multiple tablets as a biphasic gastroretentive floating drug delivery system for fenoverineA biphasic gastroretentive drug delivery system of fenoverine was developed to maintain constant plasma concentration. The delivery system consisted of a loading-dose tablet and a floating multiple matrix tablet prepared by the direct compression process. The drug release from biphasic GRDDS in 0.1 mol L-1HCl and SGF (enzyme free) was sustained over 12 h with buoyant properties. Stability studies showed no significant change in dissolution profiles (f2 value > 50). Based on the release kinetics, it can be concluded that the floating multiple matrix tablet containing HPMC was a particularly suitable gastroretentive drug delivery system with a zero-order release profile.

Abstract. The purpose of present study was to evaluate commercial preparations of carbamazepine tablets with respect to drug release through a defined sequence of experiments using Minitab software. The compliance of products with respect to United States Pharmacopeia (USP) dissolution test and comparison of the products with respect to drug release in different dissolution conditions is reported in the present paper. The different dissolution conditions studied include dissolution medium (1% SLS in purified water, 0.1 N HCl), volume (900 and 1,000 ml), rpm (50 rpm, 75 rpm). Studies indicated that all six products complied with USP dissolution criteria. However, the extent of influence of dissolution conditions on drug release was varied among the products. Distinct dissolution profiles were observed and there was no correlation with disintegration time in certain products. The in vitro dissolution experimentation helped in identifying the discriminatory dissolution conditions and also the formulations that were unaffected with change of dissolution variables. In summary, commercial preparations of carbamazepine vary widely in their dissolution behavior in multi dissolution run experimentation. Identifying this behavior of the products was essential as an in vitro tool for screening a good and a bad formulation.