RESUMO
Objective To study the method of preparation and blood sugar lowering effect of oral chitosan-insulin nanoparticles (INS-NPs) in streptozotocin-induced diabetic Wistar rats. Methods The INS-NPs were prepared by an ionic gelation method. The changes in the morphology and size of the INS-NPs were observed with transmission electron microscope and Zetasizer 3000HS, respectively. The blood sugar lowering effect of the INS-NPs was evaluated by monitoring the blood glucose levels in healthy and streptozotocin-induced diabetic rats. Results INS-NPs were spherical in shape with a mean size of 220.6±15.9nm. Entrapment efficiency of INS-NPs was 75.4%±3.2% and the loading efficiency of INS-NPs was 19.5%±2.6%. In vivo blood sugar lowering study showed that the levels of blood glucose of healthy Wistar rats were significantly reduced from 6h to 12h after oral administration of INS-NPs(25U/kg). The blood glucose level of diabetic rats were significantly reduced at 6h after oral administration of INS-NPs (25U/kg), and this effect was maintained for more than 9h, and the levels of blood glucose were kept in normal range for 7h. Conclusion The INS-NPs prepared by ionic gelation method has the blood glucose lowering effect in streptozotocin-induced diabetic Wistar rats.