Fabrication and evaluation of chondroitin sulfate based hydrogels loaded with chitosan nanoparticles for oral delivery of vildagliptin

Vildagliptin is a drug of choice in type II diabetes mellitus that suffers from limitations like short half-life with reduced bioavailability. To improve the therapeutic performance of vildagliptin, this study aimed to synthesize chitosan nanoparticles (NPs) loaded hydrogel by using biological polysaccharides like sodium alginate (SA) and chondroitin sulfate (CS). The NPs were prepared by ionic gelation method and various characterization tests like surface morphology, size and zeta potential, entrapment efficiency, and in-vitro drug release studies were performed. Results indicated that NPs were round in geometry with an average particle size of 213 nm, having drug encapsulation efficiency of 65 % and controlled drug release within 6-8 h. The optimized NPs (F2) loaded hydrogel showed a good dynamic swelling with gel fraction of 96 %. The hydrogels released 96 % of vildagliptin in 72 h via a non-Fickian diffusion mechanism. The optimized formulation was thermally stable. Formulation showed greater swelling at slight basic pH 7.4 as compared to acidic medium. Moreover, acute toxicity study results demonstrated that the developed NPs loaded hydrogel were safe for oral delivery. The overall results suggested that vildagliptin-loaded NPs loaded hydrogel can serve as an alternative novel dosage form for oral controlled drug delivery.