Core-in-cup tablet design of metoprolol succinate and its evaluation for controlled release.

The core-in-cup matrix tablets of Metoprolol succinate were prepared by wet granulation technique. Of all the investigated formulations, the optimized formulation of MS-09 followed zero-order kinetics of drug release. Trail on MS-09 was formulated using 7.5% hydrogenated castor-oil (HCO) and 4% of hydroxyl propyl methylcellulose (HPMC K15M) with an objective to achieve a linear release profile for 24 h. There is no initial burst release, with 16.17% of drug released during the first hour and release was extended up to 24 hrs. Study of drug release kinetics was performed by application of dissolution data to various kinetic equations like zero-order; first order, Higuchi and Korsmeyer-Peppas, from R(2) value (0.9975) it was concluded that the drug release followed zero order kinetics with both erosion and diffusion as the release mechanisms.