A method for the preparation of sustained release-coated Metoprolol Succinate pellet-containing tablets.

The purpose of this study was to develop a method to prepare Metoprolol Succinate (MS) sustained release pellets and compress them into pellet-containing tablets without losing sustained release property. The drug layered pellets were coated with Eudragit NE 30D to obtain a sustained release (SR) property. The mechanical properties and permeability of the coating film were tailored by adjusting the proportion of talc in the coating dispersion and the weight gain of the coating film. Pellets with different MS release rates were tested and then mixed together by different ratios to optimize drug release rate. The mixed pellets were compressed into tablets with cushioning excipients. The results showed that when the ratio of talc and coating material was 1:4, the coating operation could be conducted successfully without pellet conglutination and the mechanical property of the coating film was enhanced to withstand the compress force during tableting. Blending SR-coated pellets of 20% weight gain with SR-coated pellets of 40% weight gain at the ratio of 1:5 could produce a constant and desired drug release rate. The formulation and the procedure developed in the study were suitable to prepare MS pellet-containing tablets with selected SR properties.