Fabrication and Characterization of Sustained Release Beads of Carbamazepine by Extrusion – Spheronization Containing Carbopol®974

Abstract

The erratic absorption of Carbamazepine, BCS Class II drug, due to low water solubility and anticholinergic properties can be minimized by developing sustained release beads. Sustained release beads of Carbamazepine were prepared using axial single screw extruder and a chequered plate spheronizer. Beads offer therapeutic advantages such as easy dispersion in the gastro-intestinal tract, lower risk of dose dumping, reduce peak plasma fluctuations and drug release is independent of gastric emptying. Extrusion-Spheronization offers matrix beads with a narrow particle size distribution obviating the coating step and is economical. The process variables studied were wet mass mixing time, extruder speed, type and die size, spheronization dwell time and disc speed and drying. The present work also discusses the role of Carbopol^® 974P as a sustained release polymer for peroral delivery, which otherwise finds uses in topical and ocular delivery. Sustained release beads of Carbamazepine were successfully formulated using extrusion-spheronization. The beads were evaluated for assay, sphericity, flow properties and particle size distribution, stability, etc., and met the in vitro dissolution specifications as per USP without subsequent coating.