Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Pharmacology & Pharmacy, Oral drug absorption, Fasted state, Fed state, Luminal environment, Unstirred water layer, Imaging techniques, UNSTIRRED WATER LAYER, OROCECAL TRANSIT-TIME, MUCUS GEL LAYER, SOLUBILITY-PERMEABILITY INTERPLAY, SUSTAINED-RELEASE FORMULATION, UPPER SMALL-INTESTINE, IN-VITRO SIMULATION, FED STATE, USSING CHAMBER, BREATH TEST, Administration, Oral, Adult, Chemistry, Pharmaceutical, Computer Simulation, Drug Delivery Systems, Gastrointestinal Absorption, Gastrointestinal Tract, Humans, Intestinal Absorption, 1115 Pharmacology and Pharmaceutical Sciences, 3214 Pharmacology and pharmaceutical sciences

Abstract:

Oral administration is the most common route of drug delivery. The absorption of a drug from the gut into the bloodstream involves disintegration of the solid dosage form, dissolution of the active pharmaceutical ingredient and its transport across the gut wall. The efficiency of these processes is determined by highly complex and dynamic interplay between the gastrointestinal tract, the dosage form and the API. The European Network on Understanding Gastrointestinal Absorption-related Processes (UNGAP) aims to improve our understanding of intestinal drug absorption by creating a multidisciplinary Network of researchers from academia and industry engaging in scientific discussions. As part of the basis for the UNGAP project, this review aims to summarize the current knowledge on anatomy and physiology of the human gastrointestinal tract with emphasis on human studies for the evaluation of the regional drug absorption and the prediction of oral dosage form performance. A range of factors and methods will be considered, including imaging methods, intraluminal sampling and, models for predicting segmental/regional absorption. In addition, in vitro and in silico methods to evaluate regional drug absorption will be discussed. This will provide the basis for further work on improving predictions for the in vivo behavior of drug products in the gastrointestinal tract.