title: Navigating the human gastrointestinal tract for oral drug delivery: Uncharted waters and new frontiers.
abstract: Many concepts of oral drug delivery are based on our comprehension of human gastrointestinal physiology. Unfortunately, we tend to oversimplify the complex interplay between the various physiological factors in the human gut and, in particular, the dynamics of these transit conditions to which oral dosage forms are exposed. Recent advances in spatial and temporal resolution of medical instrumentation as well as improved access to these technologies have facilitated clinical trials to characterize the dynamic processes within the human gastrointestinal tract. These studies have shown that highly relevant parameters such as fluid volumes, dosage form movement, and pH values in the lumen of the upper GI tract are very dynamic. As a result of these new insights into the human gastrointestinal environment, some common concepts and ideas of oral drug delivery are no longer valid and have to be reviewed in order to ensure efficacy and safety of oral drug therapy.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany; Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Mirko
authors.initials: M
authors.lastname: Koziolek
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Grimm
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Schneider
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Jedamzik
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Sager
authors.affiliation: Department of Diagnostic Radiology and Neuroradiology, Ernst-Moritz-Arndt-University, Ferdinand-Sauerbruch-Strasse, Greifswald D-17475, Germany.
authors.forename: Jens-Peter
authors.initials: JP
authors.lastname: Kühn
authors.affiliation: Department of Clinical Pharmacology, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Siegmund
authors.affiliation: Department of Pharmaceutical Technology and Biopharmacy, Center of Drug Absorption and Transport, Ernst-Moritz-Arndt-University, Felix-Hausdorff-Strasse 3, D-17487 Greifswald, Germany. Electronic address: werner.weitschies@uni-greifswald.de.
authors.forename: Werner
authors.initials: W
authors.lastname: Weitschies
mesh_terms: D000284:Administration, Oral; D016503:Drug Delivery Systems; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations
keywords: Absorption window; Biorelevant dissolution testing; Drug absorption; Food effect; Gastrointestinal dynamics; Gastrointestinal hydrodynamics; Gastrointestinal motility; Oral drug delivery