Hypoglycemic effect of liposome-entrapped insulin administered by various routes into normal rats.

We entrapped insulin into liposomes using one combination of lipids comprising egg lecithin-cholesterol-stearylamine (7:2:1 molar ratio). The efficiency of entrapment was about 20% with unsonicated liposomes (LMV), and around 5% with sonicated liposomes (SUV). LMV-, SUV- and free-insulins were administered via different routes into male, non-diabetic Wistar rats in order to change the glycemia. When administered parenterally all preparations acted in a similar manner, reducing the glycemia after 2 h in the range of 75% to 85% in case of iv administration, and 43% to 67%--after sc administration. Only liposome insulin acted via intragastric route, and SUV-insulin-via buccal--or nasal route.