In Vitro And In Vivo Profiles And Characterization Of Insulin Nanocarriers Based In Flexible Liposomes Designed For Oral Administration
Alternatives routes of delivery for Insulin have been evaluated to improve treatment for Diabetes Mellitus. The oral route is the most convenient physiologically; it releases in a similar way to endogenous secretion. Flexible liposomes have deformable abilities to pass through membranes with adequate therapeutic effects, but they have been tested only dermally.
Our aim was to develop an oral nanocarrier based on flexible liposomes for insulin with polymer addition to reduce gastrointestinal degradation.
Different percentages of polyethylene glycol were added to a conventional formulation of flexible liposomes. The manufacturing procedure was the heating method. Z potential, size particle, polydispersity index and encapsulation percentage were evaluated. A release profile was performed in the stomach and intestinal pH mediums by two-stage reverse dialysis method. The in-vivo test was performed in experimental diabetic rats by oral, transdermal and subcutaneous routes.
All the formulations showed polydispersity but adequate Z potential. The 10% PEG formulation obtained the best insulin enclosure with 81.9%. The insulin integrity after preparation was confirmed by polyacrylamide gel electrophoresis. PEG and non-PEG formulations showed similar behavior in acid release profile but the release and stability of lipid structures were better and longer in intestinal pH conditions. In vivo tests showed a reduction to normal glucose levels only in subcutaneous route.
The polymer inclusion in flexible liposomes generates an adequate nanocarrier for proteins in terms of stability and composition; although its in-vivo use reduces glucose levels in subcutaneous route, the effect was not adequate in oral route.