Oral insulin delivery in diabetic rats by PLGA Nanoparticles combined with a protease inhibitor (N-Ethylmaleimide)

Nanoparticles (NP) have shown a certain potential to overcome the drawbacks of oral peptide delivery in the gastrointestinal tract such as low peptide stability and permeability. Insulin PLGA NP were prepared using a modified double emulsion solvent evaporation technique. Insulin PLGA NP were composed from human insulin (5 mg) encapsulated in PLGA 2.5% w/v mixed with PEG (2 kDa, 5% w/w) and the external aqueous phase contained 1.25% of PVA. The resulting nanoparticles of 202.6 nm diameter and loaded with 33.86 pg insulin per mg of polymer were utilised in this study to examine the hypoglycaemic effect after combination with a protease inhibitor, N-Ethylmaleimide.