Formulation and Evaluation of Floating Microspheres for Oedema

Oral gastroretentative dosage forms offer many advantages for drugs having absorption from upper gastrointestinal tract and improve the bioavailability of medication that is characterized by narrow absorption window. The purpose of present study was to formulate and develop a new gastroretentative controlled release diffusion of furosemide from the cellulose acetate floating microspheres. Furosemide is a widely used highceiling loop diuretic drug with low bioavailability (60-70 %) and shorter halflife (1-2 hrs). The microspheres were prepared by using o/w emulsion solvent evaporation method. The formulated floating microspheres were characterized for their micromeritic properties, surface morphology by SEM, in-vitro buoyancy studies, percentage drug entrapment efficiency and invitro drug release studies. Optimization studies were carried out by taking organic phase volume and drug: polymer ratio as independent variables and percentage drug entrapment efficiency and time percentage yield and size as responses using 3-level factorial design. The prepared microsphere formulations having percentage drug entrapment of 78.4%, and buoyancy of 89.42% with floating time up to 12 hours.