79EFFECT OF HYDROPHILIC AND HYDROPHOBIC POLYMERS ON METFORMIN HYDROCHLORIDE SUSTAINED RELEASE MATRIX TABLETSThe investigation was concerned with design and characterization of oral sustained release matrix tablets of metformin hydrochloride, in order to improve efficacy and better patient compliance. Tablets were prepared by wet granulation method using various hydrophilic polymers viz: HPMC K15M, HPMC 1LAKH alone or in combination with hydrophobic polymer like EUDRAGIT S100. In vitro release studies were performed using USP XXIII type II apparatus (paddle method). Compatibility of the drug with various polymers was also studied. Dissolution study revealed that either HPMC K15M or HPMC 1LAKH or combination of these two polymers of tablet preparations were able to sustain the drug release up to within 16 hours, but as well as EUDRGIT S100 combination with HPMC K15M and HPMC 1LAKH are able to sustaining the drug release for 20 hours. The formulation (F4) shows the maximum drug release of 98.14% and also extended up to 20 hours. prathap.nil@gmail.comResearch322012Metformin,Hydroxypropyl methyl cellulose,Eudragit,Evaluation parameters, in vitro releaseM. Prathap,D. Dhachinamoorthi,T. Silambarasi,S. Parthiban,A. Vikneswari,K. KarthickDepartment of Pharmaceutics, A.M.Reddy Memorial College of Pharmacy, Narasaraopet, Guntur, Andhra Pradesh, India.,Department of Pharmaceutics, QIS College of Pharmacy, Ongole, Andhra Pradesh, India.,Department of Pharmaceutical Technology, Anna University of Technology, Trichirappalli, Tamilndu, India,Department of pharmaceutics, Bharathi College of pharmacy, Bharath nagar, Mandya, Karnataka, India.,Department of Pharmacy, IIMT College of Medical Sciences, Ganga Nagar, Meerut, Uttar Pradesh, India., Department of Pharmaceutics, Zydus cadila health care pvt ltd, Ahmedabad, India.