Intestinal permeability and its relevance for absorption and elimination
2007 (English)In: Xenobiotica, ISSN 0049-8254, E-ISSN 1366-5928, Vol. 37, no 10-11, 1015-1051 p.Article in journal (Refereed) Published
Human jejunal permeability (P-eff) is determined in the intestinal region with the highest expression of carrier proteins and largest surface area. Intestinal P-eff are often based on multiple parallel transport processes. Site-specific jejunal P-eff cannot reflect the permeability along the intestinal tract, but they are useful for approximating the fraction oral dose absorbed. It seems like drugs with a jejunal P-eff > 1. 5 x 10(-4) cm s(-1) will be completely absorbed no matter which transport mechanism(s) are utilized. Many drugs that are significantly effluxed in vitro have a rapid and complete intestinal absorption (i.e. > 85%) mediated by passive transcellular diffusion. The determined jejunal P-eff for drugs transported mainly by absorptive carriers (such as peptide and amino acid transporters) will accurately predict the fraction of the dose absorbed as a consequence of the regional expression. The data also show that: (1) the human intestinal epithelium has a large resistance towards large and hydrophilic compounds; and (2) the paracellular route has a low contribution for compounds larger than approximately molecular weight 200. There is a need for more exploratory in vivo studies to clarify drug absorption and first-pass extraction along the intestine. One is encouraged to develop in vivo perfusion techniques for more distal parts of the gastrointestinal tract in humans. This would stimulate the development of more relevant and complex in vitro absorption models and form the basis for an accurate physiologically based pharmacokinetic modelling of oral drug absorption.
Place, publisher, year, edition, pages
2007. Vol. 37, no 10-11, 1015-1051 p.
intestinal permeability, intestinal secretion, intestinal efflux, drug absorption, bioavailability, biopharmaceutics classification system, intestinal transporters, pharmacology, pharmacokinetics, intestinal perfusion, P-glycoprotein
IdentifiersURN: urn:nbn:se:uu:diva-12031DOI: 10.1080/00498250701704819ISI: 000251334200002PubMedID: 17968735OAI: oai:DiVA.org:uu-12031DiVA: diva2:39800