Volume 3

July-September 2011

Optimization of gastric floating microspheres of dextromethorphan hydrobromide using a central composite design

Lian-Dong Hu , Wei Liu, Jian-Xue Yang, Li Li,

The purpose of this study was to prepare and evaluate the gastric floating microspheres of dextromethorphan hydrobromide that would prolong the gastric residence time and continuously release the drug in controlled manner. These microspheres were prepared by emulsion-solvent diffusion technique using ethyl cellulose (as carrier polymer) with drug in a mixture of dichloromethane and ethyl acetate. The physico-chemical properties of microspheres such as floating ability, drug loading, entrapment efficiency and in vitro drug release were investigated. The central composite design was chosen to obtain the optimum formulation. The microspheres prepared with optimal formulation were spherical with a size distribution range between 45 and 200 μm. The floating rate after 24h was (76.59±6.53) %, and the drug loading capacity and entrapment efficiency was found to be (13.79±0.93) % and (80.24±1.12) %.

Keywords: Floating Drug Delivery Systems, Floating Microspheres, Emulsion-Solvent Diffusion Method, Central Composite Design, Dextromethorphan Hydrobromide.