Formulation and Evaluation of Controlled Release Tablets of Metoprolol Succinate by - Osmotic Drug Delivery

Osmotically controlled drug delivery systems utilize the principle of osmotic pressure for the controlled delivery of active agents. The release rate of the drug from these systems is independent of the physiological factors of the gastrointestinal tract to a large extent. Metaprolol succinate β-receptor blocking agent was selected as a model drug to be formulated into osmotic drug delivery system. Elementary osmotic pump core tablets for Metaprolol succinate non- aqueous wet granulation were prepared by using osmogens like KCl. The coated tablets were drilled to different orifice sizes by using mechanical microdrill by mechanical means using softclix - modified sharp needle. The drilled orifice sizes on coated tablets were evaluated by using scanning ocular micrometer. It was observed that with an increase in osmogen content and pore size, rate of drug release was found to be increasing. The rate of drug release was found to be decreased with an increase in the membrane thickness. Based on different experimental trials, the optimized formulation was selected with respective to osmogen concentration, membrane thickness and orifice size that are following zero-order controlled release from the elementary osmotic pump tablets. The final selected elementary osmotic pump tablets have shown comparable dissolution profile with respective to marketed formulation.