Oral Delivery Of Peptide Drugs Research Articles

Niosomes for oral delivery of peptide drugs

One of the great challenges in drug delivery is the administration of peptide and protein drugs by the peroral route [ 11. There are several possibilities by which the bioavailability of these drugs might be increased. In previous investigations intestinal absorption of 9-desglycinamide 8-arginine vasopressin (DGAVP) administered in bioadhesive drug delivery systems was studied in vitro, in situ and in vivo [ 2-41. Bioadhesive drug delivery systems are assumed to stick to the intestinal mucosa which might result in an increase in absorption of the peptide across the mucosa due to the intimate contact between delivery system and absorbing membrane and/or to a prolonged residence time at the site of absorption. The absorption studies were carried out with microspheres consisting of phydroxyethylmethacrylate with or without bioadhesive polycarbophil (weakly crosslinked polyacrylic acid) coating. In vitro the bioadhesive beads resulted in a significantly higher absorption of DGAVP compared to uncoated beads. However, in vivo after direct intraduodenal administration to rat

Structural specificity of mucosal-cell transport and metabolism of peptide drugs: implication for oral peptide drug delivery.

The brush border membrane of intestinal mucosal cells contains a peptide carrier system with rather broad substrate specificity and various endo- and exopeptidase activities. Small peptide (di-/tripeptide)-type drugs with or without an N-terminal alpha-amino group, including beta-lactam antibiotics and angiotensin-converting enzyme (ACE) inhibitors, are transported by the peptide transporter. Polypeptide drugs are hydrolyzed by brush border membrane proteolytic enzymes to di-/tripeptides and amino acids. Therefore, while the intestinal brush border membrane has a carrier system facilitating the absorption of di-/tripeptide drugs, it is a major barrier limiting oral availability of polypeptide drugs. In this paper, the specificity of peptide transport and metabolism in the intestinal brush border membrane is reviewed.