Erythrocytes as Oral Delivery Systems for Human Insulin

Abstract

The use of different forms of human red blood cells as oral carrier systems for human insulin in vivo was the subject of this investigation. Male Wistar rats were made diabetic by a single intraperitoneal injection of streptozocin (100 mg/kg). Three days after the injection, rats were found diabetic as evidenced by elevated fasted blood glucose concentration (200 mg/dl or higher). Rats received orally one of the following (100 U, 2 ml): an insulin solution, a ghosts-insulin suspension, a vesicles-insulin suspension, a liposomes-ghosts-insulin suspension, or a liposomes-vesicles-insulin suspension. Free carrier suspensions or sodium chloride solution (0.9%) were also given orally as controls. Blood glucose concentration was determined just before administration and at 1, 2, 3, 4, 5, 6, and 7 hr post administration. The results show that all treatment groups, except liposomesghosts-insulin, were significantly different statistically from their respective controls (i.e., the free carriers).