Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.ejps.2023.106592
Lizenz creative commons licence
Titel (primär) Revisiting the pKa-Flux method for determining intrinsic membrane permeability
Autor Dahley, C.; Goss, K.-U.; Ebert, A. ORCID logo
Quelle European Journal of Pharmaceutical Sciences
Erscheinungsjahr 2023
Department AUC
Band/Volume 191
Seite von art. 106592
Sprache englisch
Topic T9 Healthy Planet
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.
dauerhafte UFZ-Verlinkung
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