Preparation of metformin hydrochloride sustained-release matrix pellets

Metformin hydrochloride sustained-release matrix pellets are prepared by extrusion-spheronization method.The optimal operating conditions and formulation are obtained by single-factor and orthogonal experimental design.The micromeritic characteristics and the release in vitro of these pellets are evaluated.In the process,micro-crystal cellulose(MCC) is 10%,ethyl cellulose(EC)∶stearic acid=1∶1,and 2% hypromellose(HPMC K4M) is used.The profiles of the prepared sustained-release pellets follow Higuchi equation,and have good sphericity.The developed process is reliable and the quality of the pellets is controllable.