Development and in-vitro evaluation of controlled released tablets of Metoprolol succinate

The objective of the present study was to develop controlled-release matrix tablets of metoprolol succinate, β1- selective adrenergic receptor blocking agent. The tablets were prepared by the wet granulation method. Ethanolic solutions of ethylcellulose (EC) and polyvinylpyrrolidone were used as granulating agents along with hydrophilic matrix materials like hydroxypropyl methylcellulose (HPMC) and guar gum. The granules were evaluated for angle of repose, bulk density, compressibility index, total porosity, and drug content. The tablets were subjected to weight variation test, drug content, hardness, friability, and in vitro release studies. The granules showed satisfactory flow properties, compressibility, and drug content. All the tablet formulations showed acceptable pharmacotechnical properties. The results of dissolution studies indicated that formulation F4 and F9 (HPMC-MCC: 60-126.5mg and 105-96.5mg respectively) could extend the drug release up to 24 hours. In the further formulation development process, F8 (HPMC-MCC: 105-81.5mg), the most successful formulation of the study, exhibited satisfactory drug release. All the formulations exhibited diffusion-dominated drug release.