Expanding LogP

Author(s)
Chrysoula Vraka, Sanja Mijailovic, Vanessa Fröhlich, Markus Zeilinger, Eva-Maria Klebermass, Wolfgang Wadsak, Karl-Heinz Wagner, Marcus Hacker, Markus Mitterhauser
Abstract

INTRODUCTION: Due to the high candidate exclusion rate during a drug development process, an early prediction of the pharmacokinetic behavior would be needed. Accordingly, high performance bioaffinity chromatography (HPBAC) approaches are growing in popularity, however, there is a lack of knowledge and no consensus about the relation between HPBAC measurements, in vivo distribution and blood brain barrier (BBB) penetration behavior. With respect to radiotracers, there is almost no reference data available for plasma protein binding (PPB), permeability (Pm) and the membrane coefficient (KIAM). Thus, this study was aimed at exploring the relevance of measuring PPB, Pm and KIAMfor the prediction of BBB penetration.

METHODS: Measurements of %PPB, Pm and KIAMwere performed using HPBAC. In total, 113 compounds were tested, 43 with brain uptake, 30 not showing brain uptake and 40 with known interactions with efflux transporters. Additionally, ClogP and HPLC logPowpH7.4data were collected.

RESULTS: %PPB, KIAM, Pm and ClogP values were in the same range for each of the three groups. A significant difference was observed for the HPLC logPowpH7.4between CNS penetrating drug group (CNSpos) and the non-penetrating drug group (CNSneg), as well as for the CNSnegtowards the drug group interacting with efflux transporters (DRUGefflux). However, as the other experimental data, also the HPLC logPowpH7.4showed a broad overlapping of the single values between the groupings.

CONCLUSION: Experimental reference values (logP, Pm, KIAM& PPB) of commonly used PET tracers and drugs showing different BBB penetration behavior are provided. The influence of the logP on brain uptake depends strongly on the selected method. However, using a single parameter (experimental or calculated) to predict BBB penetration or for the classification of drug groups is inexpedient.

Organisation(s)
Department of Nutritional Sciences, Department of Inorganic Chemistry
External organisation(s)
Medizinische Universität Wien, Ludwig Boltzmann Intitute Applied Diagnostics, Fachhochschule Wiener Neustadt
Journal
Nuclear Medicine and Biology
Volume
58
Pages
20-32
No. of pages
13
ISSN
0969-8051
DOI
https://doi.org/10.1016/j.nucmedbio.2017.11.007
Publication date
03-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
104004 Chemical biology, 302054 Nuclear medicine
Keywords
ASJC Scopus subject areas
Molecular Medicine, Radiology Nuclear Medicine and imaging, Cancer Research
Portal url
https://ucrisportal.univie.ac.at/en/publications/1b8bf405-552c-4c4c-b4fa-e7fc7e87c426