FORMULATION AND EVALUATION OF ONCE DAILY MATRIX TABLETS OF METOPROLOL SUCCINATE USING HYDROXYPROPYL METHYL CELLULOSE BY WET GRANULATION TECHNIQUE

The aim of the current study was to develop once-daily sustained-release matrix tablets of metoprolol succinate, Selective β₁– blocker used in cardiovascular diseases. The tablets were prepared by the wet granulation method. Ethanolic solutions of ethylcellulose (EC), polyvinylpyrrolidone K30 were used as granulating agents along with hydrophilic matrix polymer hydroxypropyl methylcellulose (HPMC K100M). The granules were evaluated for angle of repose, bulk density, compressibility index and drug content. The tablets were subjected to thickness, diameter, 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 and complied with in-house specifications for tested parameters. The results of dissolution studies indicated that batch AH₃ (Drug-to-HPMC K100M, ethyl cellulose solution (4%W/V, as granulating agent) could extend the drug release up to 24 hours. Batch AH₃ showed highest f₂ value 84.95 and MDT 8.9 hrs similar to that of reference product. The dissolution data were subjected to model fitting analysis and best fitted model was Higuchi model. All the formulations (except batch AH₃) exhibited diffusion-dominated drug release. The mechanism of drug release from batch AH₃ was diffusion coupled with erosion.