title: Is the solvation parameter model or its adaptations adequate to account for ionic interactions when characterizing stationary phases for drug impurity profiling with supercritical fluid chromatography?
abstract: Nine commercially available polar and aromatic stationary phases were characterized under supercritical fluid chromatographic (SFC) conditions. Retention data of 64 pharmaceutical compounds was acquired to generate models based on the linear solvation energy relationship (LSER) approach. Previously, adaptation of the LSER model was done in liquid chromatography by the addition of two solute descriptors to describe the influence of positive (D(+)) and negative (D(-)) charges on the retention of ionized compounds. In this study, the LSER models, with and without the ionization terms for acidic and basic solutes, were compared. The improved fits obtained for the modified models support inclusion of the D(+) and D(-) terms for pharmaceutical compounds. Moreover, the statistical significance of the new terms in the models indicates the importance of ionic interactions in the retention of pharmaceutical compounds in SFC. However, unlike characterization through the retention profiles, characterization of the stationary phases by modelling never explains the retention variance completely and thus seems less appropriate.
authors.affiliation: Vrije Universiteit Brussel (VUB), Center for Pharmaceutical Research (CePhaR), Department of Analytical Chemistry and Pharmaceutical Technology (FABI), Laarbeeklaan 103, B-1090 Brussels, Belgium. Electronic address: charlene.galea@vub.ac.be.
authors.forename: Charlene
authors.initials: C
authors.lastname: Galea
authors.affiliation: Université d'Orléans, ICOA (Institut de Chimie Organique et Analytique), UMR 7311, Pôle de Chimie, Rue de Chartres, BP 6759, F-45067 Orléans Cedex 2, France. Electronic address: caroline.west@univ-orleans.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: West
authors.affiliation: Vrije Universiteit Brussel (VUB), Center for Pharmaceutical Research (CePhaR), Department of Analytical Chemistry and Pharmaceutical Technology (FABI), Laarbeeklaan 103, B-1090 Brussels, Belgium. Electronic address: debby.mangelings@vub.ac.be.
authors.forename: Debby
authors.initials: D
authors.lastname: Mangelings
authors.affiliation: Vrije Universiteit Brussel (VUB), Center for Pharmaceutical Research (CePhaR), Department of Analytical Chemistry and Pharmaceutical Technology (FABI), Laarbeeklaan 103, B-1090 Brussels, Belgium. Electronic address: yvanvdh@vub.ac.be.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Vander Heyden
mesh_terms: D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D004340:Drug Contamination; D008956:Models, Chemical; D012995:Solubility
keywords: Charge descriptors; Drug impurity profiling; LSER; Polar stationary phases; Retention modelling