Chitosan-Coated Niosomal Nanocarriers for the Co-Delivery of Glibenclamide and Curcumin in Diabetes Mellitus

Glibenclamide (Gli), widely used in the management of type 2 diabetes mellitus (T2DM), shows low oral bioavailability, while curcumin (Cur) is limited by poor aqueous solubility and instability. This study reports the development of a niosomal co-delivery system combining hypoglycemic and antioxidant agents to improve formulation performance for T2DM. Gli and Cur were co-encapsulated into niosomal vesicles (NIOs) using the thin-film hydration method, followed by surface coating with chitosan (CS). The formulations were characterized by dynamic light scattering, scanning transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy, complemented by in vitro release studies under simulated gastrointestinal conditions. The prepared NIOs exhibited particle sizes between 413.5 and 576.9 nm, with encapsulation efficiency strongly dependent on formulation composition. The optimized system showed high encapsulation efficiency for both Gli (98.95 ± 0.87%) and Cur (91.09 ± 2.00%). In vitro release studies demonstrated enhanced release compared with the physical mixture, providing gastric protection and sustained intestinal delivery. Release kinetics indicated controlled drug release governed by diffusion- and erosion-based mechanisms. Both uncoated and CS-coated NIOs displayed good physical and osmotic stability, with CS coating further reducing drug leakage. These results highlight the potential of niosomal systems for efficient Gli and Cur administration in T2DM.