Author: Brayden D J, O’Mahony D J.
drug delivery technology, injection, infusion or by subcutaneous implants, Oral delivery, intestinal site of absorption and the physico-chemical properties of the agent, these labile compounds can be successfully formulated for oral delivery using intestinal-protective-targeting- and epithelial-permeating approaches, drug delivery industry, novel oral formulations of agents, biotech products and delivery technology, controlled release oral forms, Drug reformulation (with or without specialized delivery devices), non-injectable routes of delivery, Peptide-based biotechnology products are subject to the same hostile environment encountered by all peptides in the gastrointestinal (GI)tract , factors (Box 2)are susceptibility to degradation by the acidic pH of the stomach, metabolism by luminal, brush border and cytosolic peptidases, and poor permeability across the intestinal epithelium because of size, charge and hydrophilicity, Physiological considerations, such as gastric transit time, dilution and interaction with intestinal debris, also influence peptide contact with the absorptive epithelium of the most appropriate-ate intestinal region, survival and delivery to the hepatic portal vein, first-pass metabolism as well as the entero-hepatic shunt, GI tract has evolved to break down dietary peptides and proteins into di-, tri- and quaternary amino acids, there is evidence to show that carefully designed peptide formulations, or even some natural soluble antigens, can be absorbed intact, albeit in low concentrations, addressing permeability issues, polar molecular surface area, permeability coefficients can be achieved in the chemical-design stages of synthesis, small or large changes in solubility or permeability of a particular molecule will make a significant difference to oral bioavailability, epithelial tight-junction opener, is approved as an excipient, effective absorption, transepithelial resistance was reduced and the flux of the paracellular marker, paracellular transport alone could not account for adequate and sustained absorption, chemical enhancers or surfactant-like agents, particulate formulation to receptor sites on the brush border of the intestine, Human cell culture monolayer models, small intestine , transcellular carrier-mediated transport, Caco-2 intestinal cell model, receptor expression patterns, intrinsic factor-dependent uptake, apical membrane receptor, capacity for transport across epithelia, proton-dependent dipeptide transporter
