title: Exploring gastrointestinal variables affecting drug and formulation behavior: Methodologies, challenges and opportunities.
abstract: Various gastrointestinal (GI) factors affect drug and formulation behavior after oral administration, including GI transfer, motility, pH and GI fluid volume and composition. An in-depth understanding of these physiological and anatomical variables is critical for a continued progress in oral drug development. In this review, different methodologies (invasive versus non-invasive) to explore the impact of physiological variables on formulation behavior in the human GI tract are presented, revealing their strengths and limitations. The techniques mentioned allow for an improved understanding of the role of following GI variables: gastric emptying (magnetic resonance imaging (MRI), scintigraphy, acetaminophen absorption technique, ultrasonography, breath test, intraluminal sampling and telemetry), motility (MRI, small intestinal/colonic manometry and telemetry), GI volume changes (MRI and ultrasonography), temperature (telemetry) and intraluminal pH (intraluminal sampling and telemetry).
authors.affiliation: Drug Delivery & Disposition, KU Leuven, Leuven, Belgium; College of Pharmacy, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Bart
authors.initials: B
authors.lastname: Hens
authors.affiliation: Nottingham Digestive Diseases Centre and NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases at Nottingham University Hospitals NHS Trust and the University of Nottingham, United Kingdom; Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium.
authors.forename: Maura
authors.initials: M
authors.lastname: Corsetti
authors.affiliation: Nottingham Digestive Diseases Centre and NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases at Nottingham University Hospitals NHS Trust and the University of Nottingham, United Kingdom.
authors.forename: Robin
authors.initials: R
authors.lastname: Spiller
authors.affiliation: Nottingham Digestive Diseases Centre and NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases at Nottingham University Hospitals NHS Trust and the University of Nottingham, United Kingdom.
authors.forename: Luca
authors.initials: L
authors.lastname: Marciani
authors.affiliation: Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium.
authors.forename: Tim
authors.initials: T
authors.lastname: Vanuytsel
authors.affiliation: Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Tack
authors.affiliation: Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
authors.forename: Arjang
authors.initials: A
authors.lastname: Talattof
authors.affiliation: College of Pharmacy, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Amidon
authors.affiliation: Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; Center of Drug Absorption and Transport, Department of Pharmaceutical Technology and Biopharmacy, University of Greifswald, Greifswald, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Koziolek
authors.affiliation: Center of Drug Absorption and Transport, Department of Pharmaceutical Technology and Biopharmacy, University of Greifswald, Greifswald, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Weitschies
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Clive G
authors.initials: CG
authors.lastname: Wilson
authors.affiliation: Academic Medical Center Amsterdam, Department of Nuclear Medicine, Amsterdam, The Netherlands.
authors.forename: Roelof J
authors.initials: RJ
authors.lastname: Bennink
authors.affiliation: Drug Delivery & Disposition, KU Leuven, Leuven, Belgium.
authors.forename: Joachim
authors.initials: J
authors.lastname: Brouwers
authors.affiliation: Drug Delivery & Disposition, KU Leuven, Leuven, Belgium. Electronic address: patrick.augustijns@kuleuven.be.
authors.forename: Patrick
authors.initials: P
authors.lastname: Augustijns
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D005746:Gastric Emptying / Q000187:drug effects; D005769:Gastrointestinal Motility / Q000187:drug effects; D041981:Gastrointestinal Tract / Q000378:metabolism*; D005772:Gastrointestinal Transit / Q000187:drug effects; D006801:Humans; D004364:Pharmaceutical Preparations / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations
keywords: Intestinal absorption; Intraluminal profiling; MRI; Manometry; Scintigraphy; Telemetry