ABSTRACT:
The rationale of this study was to develop a sustained release microspheres formulation containing metoprolol succinate. The various batches of microspheres were prepared by cross-linking technique using chitosan polymer. The effect of stirring speed and core to coat ratio was studied with respect to entrapment efficiency and micromeritics properties. In vitro release study was performed in phosphate buffer (pH 6.8). Shape and surface analysis are also examined by scanning electron microscope. The microspheres obtained from cross-linking technique were spherical and free flow in nature. The drug content was ranges from 65.62% -72.06%. Entrapment efficiency was based on the ratio of polymer present in formulation. This is due to high loss of drug during formulation. Particle size ranged from 330 to 540µm. Microspheres was spherical in shape and having a smooth surface as the evident in Scanning electron microscopic photographs. Drug crystals was found outer surface of microspheres in formulation F1, whereas, it was absent in F4 (1:5 ratio). In vitro release study shows a better sustained effect in F3 (1:3 ratio) over 24hrs. The release data was determined using various kinetic models and korsmeyer – peppas model showed an acceptable regression value for all composition. Thus, its follows non -fickians transport mechanism and the drug release was extended up to 96.78% over period of time. This micro particulate system proves the efficient in the delivering of drug in the system over extended period of time with minimal dose.