Once-Daily Sustained Release Matrix Tablets of Metoprolol Succinate

The purpose of the present study was to design and evaluate once-daily sustained release matrix tablets of metoprolol succinate by direct compression method, to overcome its side effects, to increase its bioavailability, to reduce the dosing frequency and improve the patient compliance. The tablets were prepared using hydroxypropyl methylcellulose (HPMC) K4M and K10M (synthetic), guar gum and xanthan gum (natural) carbopol 934p and Eudragit L-100 lactose as a channeling agent. Prepared matrix tablets were evaluated for various parameters like hardness, thickness, weight variation, friability and percent drug content. Tablet formulations were subjected to in-vitro drug release studies as per USP guidelines. All the prepared formulations showed fi rst-order release kinetics with matrix diffusion mechanism of drug release. The formulation F 12 containing drug: xanthan gum ratio of 1:3:1, carbopol 934p 1:3:1 offered the required in-vitro drug release rate according to the offi cial limits of drug release as per USP and selected as a promising formulation among the fi fteen formulations. The combination of release retarding polymer and release modifying agent can effectively control the drug release for freely watersoluble drugs over a period of 24 h in case of once-daily sustained release matrix tablet formulations which are the upcoming dosage forms for patient compliance in all aspects.