Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1016/j.ejps.2023.106592 |
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| Title (Primary) | Revisiting the pKa-Flux method for determining intrinsic membrane permeability |
| Author | Dahley, C.; Goss, K.-U.; Ebert, A.
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| Source Titel | European Journal of Pharmaceutical Sciences |
| Year | 2023 |
| Department | AUC |
| Volume | 191 |
| Page From | art. 106592 |
| Language | englisch |
| Topic | T9 Healthy Planet |
| Supplements | https://ars.els-cdn.com/content/image/1-s2.0-S0928098723002221-mmc1.pdf |
| Keywords | pKa-Flux method; passive permeability; aqueous boundary layer; concentration-shift; MDCK; Caco-2 |
| 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. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=27998 |
| Dahley, C., Goss, K.-U., Ebert, A. (2023): Revisiting the pKa-Flux method for determining intrinsic membrane permeability Eur. J. Pharm. Sci. 191 , art. 106592 10.1016/j.ejps.2023.106592 |
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