PREPARATION AND CHARACTERIZATION OF HOLLOW MICROSPHERE OF VILDAGLIPTIN FOR ENHANCEMENT FOR ORAL BIOAVAILABILITY

The present investigation was aimed at the development and evaluation of a gastro-retentive hollow microsphere system for the sustained oral delivery of vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor used in the management of type 2 diabetes mellitus. Conventional oral administration of vildagliptin is associated with a short biological half-life and frequent dosing, which may compromise patient compliance. To address these limitations, floating hollow microspheres were formulated to prolong gastric residence time and provide controlled drug release. Preformulation studies were carried out to evaluate the physicochemical properties, purity, and stability of vildagliptin, confirming its suitability for formulation development. Vildagliptin-loaded hollow microspheres were prepared by the solvent evaporation technique using hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC), and guar gum in varying ratios. The prepared microspheres were evaluated for percentage yield, drug entrapment efficiency, buoyancy, particle size, zeta potential, surface morphology, and in vitro drug release behavior. The optimized formulation (F4) exhibited high entrapment efficiency, prolonged buoyancy, acceptable particle size, and good stability. Scanning electron microscopy revealed spherical microspheres with smooth surfaces and a hollow structure. In vitro release studies demonstrated sustained drug release for up to 12 hours, and release kinetics followed the Korsmeyer–Peppas model, indicating a non-Fickian diffusion mechanism. Accelerated stability studies confirmed the stability of the optimized formulation. The developed gastro-retentive hollow microspheres of vildagliptin offer a promising strategy for improving gastric retention, sustaining drug release, and enhancing therapeutic efficacy and patient compliance.