Fabrication and <i>in vitro</i> evaluation of sodium alginate-metformin loaded biopolymeric microsphere coated with chitosan for sustained drug release for the treatment of type 2 diabetes

The main objective of this present study was to develop sodium alginate-based metformin hydrochloride loaded and chitosan coated microsphere for effective treatment of type 2 diabetes mellitus. The prepared microspheres were formulated with different concentration of drug and polymer ratio and CaCl₂ was used as a crosslinking agent. Ionotropic gelation technique was adopted to prepare the microsphere in eight different drug polymer ratios. The microspheres were characterized by moisture content, microsphere size, swelling ratio, drug entrapment efficiency, <i>in-vitro</i> drug release profile for optimization purpose. Optimized formulation (F8) was further evaluated for surface morphology, FTIR, XRD, thermal analysis (TGA, DSC), antioxidant activity, <i>in-vitro</i> antidiabetic activity, and cytotoxicity studies. The microspheres were spherical in shape with shiny appearance. The average diameter of prepared microsphere was 792 ± 28.06 μm in diameter. The percentage of drug entrapment efficiency was observed in the range of 22.50 ± 2.05 to 65.41 ± 4.12%. F8 provides 39.22 ± 0.22% sustained drug release after 8 h. This approach of the fabrication of biopolymeric oral dosage form may be inspiring globally for green manufacturing of sustained release microsphere through quality-driven development.