Oral Insulin Delivery in Diabetic Rats by PLGA Nanoparticles Combined with a Protease Inhibitor (N-Ethylmaleimide)

Nanoparticles have shown a certain potential to overcome thedrawbacks of oral peptide delivery in the gastrointestinal tract such as lowpeptide stability and permeability. Insulin PLGA NP were prepared using amodified double emulsion solvent evaporation technique. Insulin PLGA NP were composedfrom human insulin (5 mg) encapsulated in PLGA 2.5% (w/v) mixed with PEG (2kDa, 5% w/w) and the external aqueous phase contained 1.25% of PVA. Theresulting nanoparticles of 202.6 nm diameter and loaded with 33.86 μg insulinper mg of polymer were utilised in this study to examine the hypoglycaemiceffect after combination with a protease inhibitor, N-Ethylmaleimide.