470FORMULATION AND EVALUATION OF MATRIX TABLETS OF BOSENTAN FOR CONTROLLED RELEASEIn this present research, an attempt has been made to formulate modified release oral matrix tablets of Bosentan using HPMC K15, Eudragit RSPO, Karaya gum and Guar Gum as rate controlling polymer for the treatment of hypertension and chronic heart failure. The tablets were prepared by wet granulation method and studied the effect of the matrix forming agents such as Guar Gum and Karaya gum separately. Tablets were evaluated for uniformity of weight, drug content, friability, hardness, thickness, swelling study, in vitro drug release study and finally stability study. All the formulations have shown compliance with pharmacopoeial standards. As the time increases, the swelling index was increased, later on decreases gradually due to dissolution of outer most gel barrier of tablet into the dissolution medium. Comparison between HPMC K15 and Eudragit RSPO, it has been observed that swelling index of Hydroxypropyl methyl cellulose (HPMC K15) was significantly more compared to Eudragit RSPO. Similarly, comparison between Karaya gum and Guar Gum, it has been observed that swelling index of Karaya gum was significantly more compared to Guar Gum. The drug release study shows that an increase amount of polymer resulted in retarded drug release. The maximum drug release was found to be 97.73% over a period of 12 hours in Karaya gum based formulations (XT9-XT12) at a concentration ranging from 15 to 60mg per tablet. Similarly maximum drug release was found to be 95.72% over a period of 12 hours in Guar Gum based formulations (XT13- XT16) at a concentration ranging from 15 to 60mg per tablet. The drug release from optimized formulation (XT12) fitted to various kinetic models and the drug release was found to follow zero-order kinetics and diffusion release mechanism. This modified release matrix tablet dosage form would be a great formulation for the treatment of hypertension and chronic heart failure by improving patient compliance and reducing dosing frequencymcanjipharma@gmail.comResearch562014Bosentan,Hydroxypropyl methyl cellulose (HPMC K15),Eudragit RSPO,Guar Gum, Karaya gum,matrix tabletsV. Anjaneyulu,K. Gnanaprakash,K.B. ChandrasekharResearch Scholar, Department of Pharmacy, Jawaharlal Nehru Technological University Anantapur, Anantapuramu-515002, Andhra Pradesh, India,Department of Pharmaceutics, Ratnam Institute of Pharmacy, Pidathapolur, Nellore - 524346 Andhra Pradesh, India,Department of Chemistry, Jawaharlal Nehru Technological University Anantapur, Anantapuramu, Andhra Pradesh, India