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Updated: Mar 13, 2026

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique
Published on: May 26, 2021
Trospium chloride is absorbed from two intestinal "absorption windows" with different permeability in healthy
Tobias Tadken1, Michael Weiss2, Christiane Modess1
1Department of Clinical Pharmacology, Center of Drug Absorption and Transport, University Medicine of Greifswald, Greifswald, Germany.
Abstract:
Intestinal P-glycoprotein is regio-selectively expressed and is a high affinity, low capacity efflux carrier for the cationic, poorly permeable trospium. Organic cation transporter 1 (OCT1) provides lower affinity but higher capacity for trospium uptake. To evaluate regional intestinal permeability, absorption profiles after gastric infusion of trospium chloride (30mg/250ml=[I]2) for 6h and after swallowing 30mg immediate-release tablets in fasted and fed healthy subjects, were evaluated using an inverse Gaussian density function to model input rate and mean absorption time (MAT). Trospium chloride was slowly absorbed (MAT ∼10h) after gastric infusion involving two processes with different input rates, peaking at about 3h and 7h. Input rates and MAT were influenced by dosage form and meal. In conclusion, trospium is absorbed from two "windows" located in the jejunum and cecum/ascending colon, whose uptake capacity might result from local abundance and functional interplay of P-glycoprotein and OCT1.
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