Formulation and Evaluation of Metoprolol Controlled Release Formulations

Aim: The main perspective of the present research work was to prepare Metoprolol floating controlled release formulations.

Methodology: After performing the characterization studies, Metoprolol tablets were prepared using various concentrations of poly ethylene oxide (PEO) WSR 303 (5% to 30%) by direct compression method. Formulations MP1 and MP6 were formulated using PEO WSR 303. Various pre and post compression parameters were evaluated. Dissolution studies were performed for the prepared tablets using dissolution medium of 0.1N hydrochloric acid.

Results: Characterization studies like Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) for Metoprolol, Polyethylene oxide WSR 303 and their combination were carried out, which revealed that there is no interaction between drug and polymer. The dissolution studies showed the controlled release pattern of Metoprolol up to 24h. The formulation MP5 prepared using 25% w/w of PEO WSR 303 showed maximum drug release of 98.22% at 24h. Similar drug release profile was observed for MP6 which was formulated using 30%w/w PEO WSR 303. These two formulations were further added with various concentrations of sodium bicarbonate (5% to 15%) and citric acid (2.5% to 10%) which enhanced floating of drug. Formulation MP8 containing 10% of sodium bicarbonate with 25% PEO WSR 303 showed less buoyancy lag time and prolonged drug release. Formulation MP15 showed very less buoyancy lag time of 4sec.

Conclusion: Thus the prepared Metoprolol floating tablets showed prolonged drug release which could be a promising formulation for anti-hypertensive patients.