Although some progress has been made in recent years in the study of non-injection pathway sedatives for peptides, many difficulties are still encountered. Almost all peptide drugs require mucosal transfer of osmosis promoters, and their variety, the problem is how to reduce its stimulating effect and whether long-term use affects epithelial integrity.
Replacing osmosis promoters with particles may be a promising oral administration. At present, although some achievements have been made in overcoming osmosis and enzyme barriers, no breakthrough has been made. In addition, the problem of liver removal of peptides should be paid attention to, to understand the relationship between liver removal mechanism, structure and removal will help to realize the dream of polypeptide oral administration.