Abstract
The development of an oral insulin therapy remains an ultimate goal to both enhance ease of use, and to provide therapeutic advantages rooted in its direct delivery to the portal vein and liver. The current study aimed to develop a novel formula for insulin oral administration against experimental diabetes in rats. Entrapped insulin (INS) between chitosan nanoparticles (CSNPs) and layered duple hydroxide (LDH) (LDH-INS-CSNPs) was chemically prepared, and characterized by X-ray diffraction, Fourier transformation infrared, high-resolution transmission electron microscope, field emission scanning electron microscope and Zeta potential measurements. The insulin release study was conducted in vitro, while the oral hypoglycemic effect of LDH-INS-CSNPs was investigated in vivo in diabetic rats. The prepared formulas revealed a variation in the spectra of characterization methods. The insulin entrapment between LDH and chitosan avoided the burst release of insulin and acid denaturation in the stomach and enzymatic degradation throughout the gut. Consequently, the blood glucose level of LDH-INS-CSNPs formula exhibited a marked hypoglycemic effect. The present work showed that the LDH-INS-CSNPs formula had a protective effect against enzymatic degradation, reduced insulin initial burst release, and enhanced bioavailability through the oral administration route. Interestingly, the presented formula could be an oral antidiabetic agent alternative to injectable insulin.