Preparation of Cefalexin Sustained-release Pellets and Investigation on Its Drug Release in Vitro

Objective To prepare cefalexin sustained release pellets and to investigate the factors affecting the release profile in vitro.Methods The cores of pellets were prepared by extrusion-spheronization.Melt coating method was used for the isolation.Optimal coating material was stearyl alcohol.Eudragit dispersions were coated as a sustained-release layer in a fluid-bed equipment.Factors affecting the release profile were investigated in vitro.Results The best formulation consisted of HPMCK4M,MCC as the matrix materials.The cefalexin sustained-release pellets coated with 8% Octadecyl Alcohol as the isolation layer and 7% coating material showed best sustained-released profile,and the coating material consisted of Eudragit N E30D,SDS(4%,w/w)in pH 7.8 PBS.Conclusion The sustained-release pellets meet the general requirements of the design.