Optimization and Characterization of Floating Microspheres of Sitagliptin Using A Polymer-Based Gastroretentive Drug Delivery Approach

Abstract

The present study focuses on the formulation and evaluation of floating sustained-release microspheres of Sitagliptin using the ionotropic gelation method. Sodium alginate and chitosan were employed as natural, biocompatible matrix-forming agents, while calcium chloride served as the cross-linking agent. A total of nine formulations (SM1–SM9) were prepared by varying polymer concentrations to assess their effects on particle size, buoyancy, entrapment efficiency, and drug release behavior. The optimized formulation, SM2, showed superior performance with high drug entrapment (72.25± 2.65%), good buoyancy (80.12±3.36%), maximum yield (76.65±2.25%), and a controlled drug release of 76.56± 2.80% over 12 hours. Scanning electron microscopy confirmed the spherical shape and smooth surface of the microspheres. Kinetic modeling indicated that drug release from SM2 followed first-order kinetics, with diffusion-controlled and non-Fickian transport mechanisms. These findings suggest that SM2 is a promising oral delivery system for improving the bioavailability and therapeutic effectiveness of Sitagliptin in the management of type 2 diabetes mellitus.