In Vitro Evaluation of Insulin Release from Chitosan-Alginate Macrobeads

Purpose Oral delivery of peptide/protein is quite difficult due to physiological barriers. Encapsulation of these drugs in the suitable biopolymeric matrix could protect the drug as well as increase the residence time of the formulation. Mucoadhesive biopolymers are being widely investigated for this purpose. Methods We have fabricated insulin-loaded chemically crosslinked chitosan-alginate macrobeads of approximate size 3 mm per bead. The beads were characterized for surface morphology and polymeric interaction using SEM, EDX, and FTIR, respectively. Results The swelling profile and insulin release were analyzed in water and PBS for 9 h. The surface had uniform undulations as observed by SEM. EDX confirmed the chemical crosslinking of chitosan and alginate. FTIR further confirmed the interaction among the polymers. The swelling study revealed a gradual increase for some time and then a decrease in weight possibly due to the disintegration of beads. A cumulative release of approximately 35% was observed by the end of 9 h in both the dissolution medium. Conclusions This work is done to investigate the possibility of release of protein/peptide drugs from polysaccharide biopolymer-based blended hydrogel matrix for possible non-invasive delivery of such drugs orally. Here, we have formulated mixed polyelectrolyte hydrogel beads of chitosan and alginate encapsulating insulin as the model drug. Our work shows a sustained release of insulin from the chitosan-alginate beads.