The aim of this present study is to develop micro-beads for controlled release of Metoprolol succinate (MS). Different combinations of alginate and poloxamer 407 (PL) were taken to prepare beads by employing ionotropic gelation method, where CaCl2 used as gelling agent. FTIR technique was used to study the drug and polymers interaction. The prepared beads were evaluated for drug loading, entrapment efficiency, particle size and morphology, in vitro drug release and drug release kinetics. There were no shift in the major peaks of the pure drug was observed from the FTIR spectra, which indicates the absence of interaction between drug and polymers. The highest drug loading and entrapment efficiency were found to be 3.11 % and 35.67 %, respectively for the formulation FB1. The particle size was measured by sieving method and it was found that the particles were in the micron range for all the formulations. The morphology of the formulation FB4 was studied by SEM and the image showed irregular surface. The in vitro drug release study was carried out in pH 6.8 phosphate buffer for 12 hr at 37ºC and the results demonstrate cumulative percentage of drug release was decreased with the increase in PL ratio in the composition that indicates controlled drug release. To know the mechanism of drug release the in vitro drug release data were fitted to zero order, first order, Higuchi and Korsmeyer-Peppas equation. The formulation FB4 showed highest correlation coefficient (r2) of 0.97 for Higuchi equation due to which it was selected as best formulation. The release exponent (n) of all the formulation were below 0.45 except FB4 (0.48) demonstrating Fickian diffusion is the drug release mechanism, whereas the formulation FB4 indicated non-Fickian diffusion i.e. diffusion and erosion were the mechanism.

Keywords: Metoprolol succinate, Micro-beads, Alginate, Poloxamer, Fickian diffusion.