Microencapsulation of ibuprofen and Eudragit (R) RS 100 by the emulsion solvent diffusion technique
The emulsion solvent diffusion was employed to prepare modified release microspheres of ibuprofen. The technique was optimised for the following processing variables: the absence/presence of baffles in the reaction vessel, agitation rate and drying time. Thereafter, the influence of various formulation factors on the microencapsulation efficiency, in vitro drug release and micromeritic properties was examined. The variables included the methacrylic polymer, Eudragit(R) RS 100, ibuprofen content and the volume of ethanol used during microencapsulation. The results obtained were then interpreted on a triangular phase diagram to map the region of microencapsulation, as well as those formulations that yielded suitable modified release ibuprofen microspheres.