Novel galactomannan-based hydrogels for enhanced stability and controlled release of insulin and erythropoietin: A promising approach in drug delivery systems

The current study focused on the hydrogel-forming capabilities of polysaccharides extracted from the endosperm of four Caesalpiniaceae seed varieties. Research has uncovered differences in the physicochemical attributes of the resulting hydrogels. The hydrogel formed from the polysaccharide of Senna alexandrina L. (SA) was a thin watery gel, whereas those from Cassia fistula L. (CF), and from two varieties of Caesalpinia pulcherima L. (orange (OC) and yellow (YC)) were thick. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses confirmed the polymerization with the crosslinking agents, and the differences in the porous morphology of each hydrogel were evident. Rheological studies of hydrogels (SA, CF, OC, and YC) revealed a weak, flexible network structure and behaved as a dilatant shear-thinning fluid. An OC and YC demonstrated higher yield stress compared to SA and CF. The XRD and FTIR analyses of hydrogels containing insulin and erythropoietin confirmed structural stability, amorphous distribution, and drug entrapment up to 91 % and 54 % respectively. The controlled release of insulin and erythropoietin from each hydrogel over 120 h was evaluated in vitro using the Korsmeyer-Peppas model. These results indicate that galactomannan-based hydrogels are a promising approach for the controlled drug delivery of insulin and erythropoietin.