The purpose of the present work was to design & evaluate sustained release tablets of Nifedipine, employing hydrophilic polymer to improve dissolution rates of the drug. METHOCEL K15MCR & METHOCEL K100LVCR were used in tablets prepared by direct compression. The formulated tablets were physicochemically characterized & results were found in acceptable limits. Poor aqueous solubility of Nifedipine leads to variable dissolution rates. The main effect & interaction terms were quantitatively evaluated using mathematical models. Dissolution data were fitted to zero order, first order, Higuchi's, Korsmeyer-Peppas & Hixson-Crowell release kinetics to evaluate kinetic data. The drug release data fit well to the Higuchi expression, but a close relationship was also noted with zero order kinetics. Korsmeyer's plot indicated that the drug release mechanism from the matrix tablet was to be found Fickian mechanism. Regulated drug release study indicate that the matrix tablets of Nifedipine prepared using above polymers can successfully be employed as twice-a-day oral controlled release dosage form.

The purpose of the present investigation was to design and evaluate sustained release tablets of a sparingly water soluble drug Ambroxol Hydrochloride, two hydrophilic polymers METHOCEL K15MCR and METHOCEL K100MCR and hydrophobic Eudragit RL100 were used in tablets prepared by direct compression. The granules were evaluated for angle of repose, loose bulk density, tapped bulk density, compressibility index, total porosity and drug content. The tablets were subjected to various tests for physical parameters such as thickness, hardness and friability, and in vitro release studies. The in vitro dissolution study was carried out for 12 hours using United States Pharmacopoeia (USP) paddle-type dissolution apparatus (Apparatus 2) in phosphate buffer (pH 6.8). The results of dissolution studies indicated that formulations containing Methocel K100 MCR showed better dissolution properties compared to formulaitons containing Methocel K15 MCR.It was found that Hydrophilic polymers showed better released profile than the hydrophobic polymers.