Floating microspheres of carvedilol as gastro retentive drug delivery system: 32 full factorial design and in vitro evaluation

Abstract

Context: Designing a sustained release system for Carvedilol to increase its residence time in the stomach.

Objective: Preparation of floating microsphere by the emulsion solvent diffusion method, studying the effect of various process parameters and optimize the formulation using full factorial design.

Methods: Different microsphere formulations were prepared by varying the ratio ethanol:dichloromethane (1:0 to 1:1.5), ethyl cellulose:hydroxypropyl methyl cellulose and stirring speed (800–1600?rpm). The effect of these variables on particle size, encapsulation parameters, surface topography, in vitro floatability and drug release were evaluated.

Results: 3² full factorial design was used for the optimization of the formulation. Drug entrapment efficiency, particle size and in vitro drug release were dependent on concentration of ethyl cellulose and stirring speed. Microspheres remained buoyant for more than 10?h and showed sustained release of the drug.

Conclusion: Floating microspheres of Carvedilol with good floating ability and sustained release were developed.