Formulation and Evaluation of Sustained Release Metoprolol Succinate Tablet using Hydrophilic gums as Release modifiers

The objective of this study was to design and evaluate oral sustained drug delivery system for Metoprolol succinate using natural hydrophilic gums such as karaya gum and xanthan gum as a release modifier. Nine batches were prepared by using karaya gum (KG) and xanthan gum (XG) in concentration of 15%, 20% and 25% alone and in combination of 2:8. Matrix tablets were prepared by wet granulation method and were evaluated for weight variation, content uniformity, friability, hardness, thickness, swelling index, in vitro dissolution, and stereo photography. Among the formulations studied, formulation F8 containing combination of KG and XG (2:8) having concentration of 20% showed sustained release of drug for 12hrs with cumulative percent release of 99.24%. The kinetic treatment showed that the optimized formulation follow zero order kinetic with release exponent (n) 0.7656 and having good stability as per ICH guidelines. No chemical interaction between drug and gums was seen as confirmed by IR studies. The matrix formulation F8 showed sustained release of Metotprolol succinate by the diffusion mechanism.