Osmotic tablets have emerged as a new technology for the delivery of drugs whose release rate is to be controlled.These tablets offer controlled drug release with the help of certain osmogens and also provide zero-order rate kinetics.In the present study, we have developed an osmotic tablet of Metformin Hydrochloride (HCL) to enhance its oral bioavailability.Metformin HCL is a biguanide derivative often used as an anti-hyperglycemic agent.The tablets were prepared using the wet granulation technique.The prepared formulations were characterized and optimized on the basis of various physicochemical properties, and F5 was selected as best.The in vitro drug release study demonstrated that the drug release depends upon the concentration of different polymers, including hydroxyl propyl methylcellulose (HPMC) and Poly ox N80 (polyethylene oxide).A higher concentration of HPMC and Poly ox N80 results in drug release for extended duration.The optimized formulation developed with a 3:1 ratio of both the polymers HPMC E5 and Poly ox N80 have shown nearly 86% of drug release.Osmotic tablets hold promising potential for increasing drug efficacy and reducing dosing frequency with minimal side effects.It also provides an economical means of developing controlled release dosage forms. INTRODUCTION:Drug release from novel drug delivery systems offers controlled release of drug at the target site for better therapeutic action.Unlike conventional therapies, it provides the advantage of predictable plasma concentrations and target it to the desired site of action and thereby reducing the dose, dosing frequency, toxic adverse effects, and blood level fluctuations.