Pulmonary administration of cross-linked chitosan nanoparticles of genistein for regulating blood glucose

The research study focused on the development and characterization of sustained release formulation of genistein (GEN)-loaded chitosan (CS) nanoparticles to deliver in the form of dry powder inhaler (DPI) via pulmonary route to offer higher stability and anti-diabetic activity. The GEN-loaded nanoparticles were prepared by cross-linking reaction of CS and sodium hexametaphosphate (SHMP). The optimized formulation displayed particle size (PS) of 684.2 ± 26.5 nm, zeta potential (ZP) of 19.6 ± 4.50 mV, % entrapment efficiency (% EE) of 87.33 ± 8.46 % and drug release profile of 85.48 ± 5.50 % for 48 h. The in-vivo studies exhibited a superior sustained release formulation of GEN in the regulation of blood glucose levels (BGLs). The powder showed the emitted fraction (EF) of 86.76 % and effective inhalation index (EI) of 85.41 %. The reduction of BGLs (85 %) was observed in the diabetic group. This might be due to the inhibition of proliferation of pancreatic β-cells (growth factor inhibition targeting cAMP and ERK1/2 pathway), antioxidative activity, reducing insulin resistance, and the adipose tissue mass and alteration of the hepatic glucose metabolism. Hence, these results proved the delivery of GEN in the form of DPI system as a favorable route for treating type-1 diabetes mellitus with a longer duration of action.