title: Validation of a rapid equilibrium dialysis approach for the measurement of plasma protein binding.
abstract: Equilibrium dialysis (ED) is one of the most frequently used approaches to investigate drug binding, where the major drawbacks are the time to reach equilibrium (varying between 6 and 24 h), a long assay preparation time and complexity of automation. A rapid equilibrium dialysis (RED) device has recently become commercially available (Pierce Biotechnology, ThermoFisher Scientific, Waltham, MA) offering the potential for reduced preparation and equilibration times. The RED device comprises a Teflon base plate which holds up to 48 disposable dialysis cells. Each dialysis insert is made up of two side-by-side chambers separated by a vertical cylinder of dialysis membrane with a high membrane surface area-to-volume ratio. An independent validation of the RED approach for the measurement of human plasma protein binding (PPB) was carried out as a comparative analysis with standard ED evaluating equilibration time, assay reproducibility and accuracy and ease of use. Using a diverse set of 18 commercially available drugs spanning a range of physicochemical properties we have shown this to be a robust and accurate methodology, with a shorter preparation and dialysis time, capable of being automated as a high-throughput assay for the determination of PPB.
authors.affiliation: Metabolism and Pharmacokinetics Group, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB, UK. nigel.waters@novartis.com
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Waters
authors.forename: Rachel
authors.initials: R
authors.lastname: Jones
authors.forename: Gareth
authors.initials: G
authors.lastname: Williams
authors.forename: Bindi
authors.initials: B
authors.lastname: Sohal
mesh_terms: D001798:Blood Proteins / Q000378:metabolism*; D002853:Chromatography, Liquid; D003956:Dialysis; D006801:Humans; D011485:Protein Binding; D053719:Tandem Mass Spectrometry
chemical_list: D001798:Blood Proteins