During the preceding forty years, type 2 diabetes has been treated with the biguanide metformin, a medication utilized all around the world. Metformin was first approved in Canada in 1972 and received subsequent FDA approval in the US in 1995. By increasing the sensitivity of the liver and muscles to insulin, it enhances glycemic management. As metformin doesn't really increase insulin release, it has no connection to hypoglycemia. Metformin's enhanced metabolic regulation does not promote excess weight and may even lead to weight decrease. Other fibrinolytic disorders, hyperinsulinemia, insulin resistance, dyslipidemia, increased plasminogen activator inhibitor 1 levels, and dyslipidemia are all positively impacted by metformin. In spite of the fact that metformin lowers insulin resistance, the cellularmode of action is not fully known. Conventional drug was effective but caused an immediate effect that drastically decrease the blood sugar level and can cause dizziness and even rapid fatigue to the patient, Lactic acidosis, allergic reactions, changed the taste, cobalamin insufficiency, hypoglycemia and GI intolerance are the most prevailed metformin adverse medication responses. Acute complications of diabetes or extreme chronic conditions (including cardiacliver, and renalfaliure) should not be used with metformin. Moreover patient has to take the repetitive dosage of the drug over a certain period of time while in the modern day extended or sustained release formulation are in action for a longer period of time, different types of polymers are used to design such tablets to encapsulate them with the ability to release an optimum amount of drug at the particular interval of time to keep the dosage level steady for longer period