Metoprolol tartrate, a nonselective beta adrenergic blocking agent, is widely used in the treatment of hypertension, angina pectoris and many other cardiovascular disorders. The bioavailability of Metoprolol tartrate is low. Metoprolol tartrate is highly water soluble drug with relatively short biological half-life of 4-5 hrs and usual dose is 25 mg thrice daily. This demands high frequency of administration resulting in oscillation of plasma drug concentration, it is necessary to develop sustained release dosage form with extended clinical effect.Metoprolol Tartrate was formulated as immediate release layer as well as sustained release layer. Это и многое другое вы найдете в книге Design and Development of tablets for the treatment of blood pressure (Vikram M. Pandya,Praful Bharadia and Niral Patel)