The objective of the present work was to formulate and to characterize controlled release matrix tablets of Fexofenadine in order to improve bioavailability and to minimize the frequency of administration and increase the patient compliance. A matrix tablets was developed that releases Fexofenadine over a 12-hour period and the influence of the polymer type and concentration on the release rate of the drug was evaluated. Fexofenadine tablets were prepared by direct compression technique by the use of different natural, synthetic polymers such as gum acacia, hydroxypropyl methyl cellulose K15, xanthum gum and guar gum individually and also in combination. Studies were carried out to study the influence of type of polymer on drug release rate, and in vitro release kinetics were examined. All the formulations were subjected to physicochemical characterization such as weight variation, hardness, thickness, friability, drug content. In vitro dissolution studies were carried out simulated gastric fluid (pH 1.2) for first 2 h and followed by simulated intestinal fluid (pH 6.8) up to 12 h, and obtained dissolution data were fitted to in vitro release kinetic equations in order to know the order of kinetics and mechanism of drug release. Formulated tablets were found to be within acceptable limits for physical and chemical parameters. Formulation containing HPMC K15 obtained the desired drug release profile up to 1h followed zero order kinetics. The release kinetics of the HPMC k15 formulation showed the best linearity (r2 =0.947) in fitting zero-order kinetics, suggesting the release rate was time independent release. Based on the results, fexofenadine controlled release matrix tablets prepared by utilizing HPMC k15 can attain the desired drug release up to 12 h. Which results in maintaining steady state concentration and improving bioavailability.
