Preparation of Metformin Biodegradable Polymeric Microparticles by O/O Emulsion Solvent Evaporation: 32 Full Factorial Design Approach.

Abstract

Background: Sustained release of synthetic polymeric microparticles have gained more attention as drug delivery carriers because of their properties such as good stability, low toxicity, dosing frequency, simple and mild preparation method. The present work was envisaged to reduce the dosing frequency by preparing drug loaded biodegradable microspheres by the O/O emulsion solvent evaporation technique. Objective: The objective behind microspheres’ preparation is to sustain the metformin release by using ethyl cellulose as a synthetic polymer. The model drug metformin having a low biological half-life (1.5-3 hours) is selected. Method: As the metformin is highly water soluble in nature, the oil-in-oil solvent evaporation techniques were used and span 80 was utilized as surfactant. The effect of stirring rate and surfactant concentration on the characteristics of encapsulation efficiency and drug release from the microsphere were investigated. Results: The results show that the drug-polymer (1:1) ratio gives better sustained release results. The obtained microparticles are characterized by X-RD analysis and Fe-SEM, and release behavior was checked for release patterns. A 32 full factorial design was employed and developed for the responses. The free-flowing spherical microspheres show high drug entrapment efficiency. Conclusion: The data obtained thus suggests that microspheres can be successfully designed for sustained release for diabetic treatment.