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Updated: Jan 31, 2026

An Intestine/Liver Microphysiological System for Drug Pharmacokinetic and Toxicological Assessment
Published on: December 3, 2020
Applications and limitations of interspecies scaling and in vitro extrapolation in pharmacokinetics
1Department of Drug Metabolism, Merck Research Laboratories, West Point, PA 19486, USA. jiunn_lin@merck.com
Abstract:
The search for new drugs is an extremely time-consuming and costly endeavor. Much of the time and cost are expended on generating data that support the efficacy and safety profiles of the drug. Because of ethical constraints, relevant pharmacological and toxicological assessments must be made in laboratory animals and in in vitro systems before human testing can begin. In support of the efficacy and safety evaluation during drug development, two fundamental challenges facing industrial drug metabolism scientists are (1) how to "scale-up" the pharmacokinetic data from animals to humans and (2) how to extrapolate the in vitro data to the in vivo situation. This review examines the applications and limitations of interspecies scaling and in vitro extrapolation in pharmacokinetics.
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