Study On Sustained-release Pellets Of Metoprolol Tartrate

Metoprolol, a β₁-selective adrenoceptor antagonist, is widely used, particularly in treatment of hypertension and coronary heart disease. It has a relatively short elimination half-life of 3-4 h, combined with a well-defined relationship between plasma concentrations and β₁-blocking effects, which makes it ideal to administrate in a sustained-release form.For drugs following oral route, if the elimination half-life is short and has to be taken in a long period of time, sustained-release delivery systems will have more important benefits over conventional ones, including achievement of steady drug concentrations within the therapeutic range, reduced frequency of administration, less adverse effects, and thereby with an improvement in patients' compliance.For oral extended release dosage form, depend on whether the formulation can be separated or not, it is divided into two forms. The first is single dosage form, which can't be separated, e.g. coated or matrix tablets and the second is multi-particulate dosage form, which can be separated and have lots of uniform sub-units, e.g. pellets and mini-tablets. Compared with each other, the latter has more advantages over the former. Take pellets for example, â‘  It can be evenly scattered in GI track, therefore less influenced by the gastric empting rate and less individual diversity.â‘¡ The release pattern of pellets is the sum results of hundreds unit forms, so flaws of individual units...