Please use this identifier to cite or link to this item: http://dx.doi.org/10.25673/111908
Title: Revisiting the pKa-Flux method for determining intrinsic membrane permeability
Author(s): Dahley, Carolin
Goss, Kai-UweLook up in the Integrated Authority File of the German National Library
Ebert, Andrea
Issue Date: 2023
Type: Article
Language: English
Abstract: Intrinsic membrane permeability is one of several factors that critically determine the intestinal absorption of a chemical. The intrinsic membrane permeability of a chemical is usually extracted from transwell experiments with Caco-2 or MDCK cells, preferably by the pKa-Flux method, which is considered the method of choice when aqueous boundary layer effects need to be excluded. The pKa-Flux method has two variants, the iso-pH method, where apical and basolateral pH are equal, and the gradient-pH method, where apical and basolateral pH are different. The most commonly used method is the gradient-pH method, as it is intended to reflect the pH-conditions in the gastrointestinal tract. However, concentration-shift effects caused by the applied pH-difference between apical and basolateral compartment in the gradient-pH method have not been considered in the evaluation of the experimental data in the past. Consequently, incorrect intrinsic membrane permeabilities have been determined. In this work, we present a revised method for extracting the intrinsic membrane permeability from gradient-pH data that considers concentration-shift effects in the basolateral aqueous boundary layer and filter as well as in the cytosol. Furthermore, we propose the use of the iso-pH method, where only concentration-shift effects in the cytosol need to be considered, as an alternative to the gradient-pH method. We use the five lipophilic bases amantadine, chloroquine, propranolol, venlafaxine and verapamil as examples to compare gradient-pH method and iso-pH method with regard to the extractability of the intrinsic membrane permeability. For lipophilic bases, the iso-pH method proves to be advantageous. All intrinsic membrane permeabilities determined in this work were substantially higher than the intrinsic membrane permeabilities reported in literature.
URI: https://opendata.uni-halle.de//handle/1981185920/113866
http://dx.doi.org/10.25673/111908
Open Access: Open access publication
License: (CC BY-NC-ND 4.0) Creative Commons Attribution NonCommercial NoDerivatives 4.0(CC BY-NC-ND 4.0) Creative Commons Attribution NonCommercial NoDerivatives 4.0
Journal Title: European journal of pharmaceutical sciences
Publisher: Elsevier
Publisher Place: New York, NY [u.a.]
Volume: 191
Original Publication: 10.1016/j.ejps.2023.106592
Appears in Collections:Open Access Publikationen der MLU

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