Abstract: This invention is directed to a pharmaceutical composition in the form of a tablet with improved stability, as well as the process for obtaining said composition. The tablet of the present invention comprises two active ingredients comprising two oral hypoglycemic agents: one phase with a sulphonylurea, such as immediate release Glimepiride, and a second phase with a biguanide, such as extended-release Metformin hydrochloride (Metformin HCl). The biphasic tablet, which can include over 500 mg of Metformin HCl (i.e. up to 1,000 or 1,500 mg, depending on the daily requirements of each patient), is to be orally administered once or twice a day. The combination of these hypoglycemic agents has a synergic effect and therefore a greater effectiveness in controlling the blood glucose level in patients with diabetes mellitus, type 2.