The interaction between copovidone and Carbopol 907 is pH dependent. When the pH of an aqueous solution fell below pH 4.5, a water-insoluble complex began to form and precipitate. This complex resulted from a hydrogen-bond-induced interaction between the carboxylic groups in Carbopol 907 and the carbonyl groups of N-vinylpyrrolidone repeat units in copovidone. Consisting of these two polymers a...

     Megaloporous controlled release tablets of diclofenac sodium (DS) were prepared with two kinds of granules. One of them is the restraining-phase matrix granule (RMG) and it controls the release rate of the drug. The other one is the soluble housing-phase matrix granule (HMG) and controls liquid penetration into the system. Carnauba wax and Eudragit L 100 polymers were used to constitute th...

Floating matrix tablets of metformin hydrochloride were developed and evaluated for increase bioavailability by increasing gastric residence time and sustained release of drug on the upper part of gastrointestinal tract thereby diminishing side effects and enhanced patient compliance. Metformin hydrochloride, an oral antidiabetic having narrow absorption window in the upper part of gastrointest...