FORMULATION AND OPTIMIZATION BY APPLYING 32 FULL FACTORIAL DESIGN OF MUCOADHESIVE MICROSPHERES OF NIFEDIPINE

Objective: The purpose of this research work is to formulate and optimize mucoadhesive microspheres of nifedipine using Carbopol 934P as mucoadhesive and ethyl cellulose as a carrier polymer for controlling the release of nifedipine. Methods: The emulsion solvent evaporation technique was used for the preparation of microspheres and the 32 full factorial designs were employed for optimization of microspheres. The developed microspheres were characterized for percent yield, entrapment efficiency, particle size, in vitro release study, percent mucoadhesion, surface morphology, and stability study. Results: Evaluating outcomes of preliminary batches indicated that 100 ml volume of processing medium, 5 h stirring time and 2% concentration of emulsifying agent were suitable for spherical, free-flowing microspheres and high percentage drug entrapment efficiency. The optimized batch exhibited 84.35% drug entrapment efficiency, 61.78% mucoadhesion and drug release were also sustained for more than 12 h. Scanning electron microscopy study revealed that produced microspheres were spherical in shape. Conclusion: Experimental responses of the optimized batch have close proximity with the predicted value and stability study of the optimized formulation proved the formulation is stable for a long period of time; hence, it is an excellent alternative over the conventional delivery system