Optimization Studies on Floating Multiparticulate Gastroretentive Drug Delivery System of Famotidine

The objective of this study was to optimize floating microballoons of famotidine by the emulsion solvent diffusion technique using central composite design. Formulations F₁–F₁₅ were prepared using three independent variables (pH of medium, drug: Eudragit® S100 ratio and ethanol : dichloromethane ratio) and evaluated for dependent variables (shape, percentage buoyancy, and encapsulation). The optimized formulation F₉ was fractionated and a polymer combination of (Eudragit® S100 : Eudragit® L100-55, 9.5:0.5) resulted in microballoons that exhibited zero order release (94.73%) with 84.20% buoyancy at the end of the eighth hour when studied in the mesh-designed modified USP type II apparatus.