Formulation and Evaluation of Gastroretentive Floating Microballoons of Norfloxacin

The present study involves preparation and evaluation of floating
microballoons with norfloxacin s model drug for prolongation of gastric
residence time. The microballoons were prepared by the solvent evaporation
method using a combination of polymer Eudragit RS 100 and Eudragit L
100. The shape and surface morphology of prepared microballoons were
characterized by optical and scanning electron microscopy, respectively. In
vitro drug release studies were performed and drug release kinetics was
evaluated using the linear regression method. Effects of stirring rate during
preparation, polymer concentration, solvent composition and dissolution
medium on the size of microballoons, and drug release were also observed.
The prepared microballoons exhibited prolonged drug release (8 hours) and
remained buoyant for >10 hours. The mean particle size increased and the
drug release rate decreased at higher polymer concentration. No significant
effect of the stirring rate during preparation on drug release was observed. In
vitro studies demonstrated diffusion-controlled drug release from the
microballoons.