An efficient pH sensitive oral insulin delivery system enhanced by deoxycholic acid

Abstract

A permeation enhancer, positively charged deoxycholyl-hyperbranched oligoethylenimine (DCO), was prepared and used to form complexes with negatively charged insulin based on electrostatic interaction. DCO/insulin complexes can be loaded into poly ( l -glutamic acid) (PGA) microspheres by the oil-in-oil (O/O) emulsion and solvent evaporation technique. Because of the specific pH sensitive properties of PGA, these insulin encapsulated microspheres are stable in the stomach and disaggregate in the small intestine, and the bioavailability of oral insulin administration will be improved due to DCO's permeation enhancement function.