title: Chromatographic resolution of closely related species: drug metabolites and analogs.
abstract: In this study, we investigate the separation of a variety of mixtures of drugs, metabolites, and related analogs including representatives of the carbamazepine, methylated xanthine, steroid hormone, nicotine, and morphine families using several automated chromatographic method development screening systems including ultra high performance liquid chromatography, core-shell HPLC, achiral supercritical fluid chromatography (SFC), and chiral SFC. Of the 138 column and mobile phase combinations examined for each mixture, a few chromatographic conditions afford the best overall performance, with a single achiral SFC method (4.6 × 250 mm, 3.0 μm GreenSep Ethyl Pyridine, 25 mM isobutylamine in methanol/CO2) affording good separation for all samples. Four of these mixtures were also resolved by achiral SFC on the Luna HILIC and chiral SFC Chiralpak IB columns using methanol or ethanol with 25 mM isobutylamine as polar modifiers. Modifications of standard chromatography screening conditions afforded fast separation methods (from 1 to 5 min) for baseline resolution of all components of each of these challenging sets of closely related compounds.
authors.affiliation: Merck Research Laboratories, Rahway, NJ, USA.
authors.forename: Erik L
authors.initials: EL
authors.lastname: Regalado
authors.forename: Roy
authors.initials: R
authors.lastname: Helmy
authors.forename: Mitchell D
authors.initials: MD
authors.lastname: Green
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Welch
mesh_terms: D002220:Carbamazepine / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D025924:Chromatography, Supercritical Fluid; D012739:Gonadal Steroid Hormones / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D015394:Molecular Structure; D009022:Morphine Derivatives / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D009538:Nicotine / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D019820:Xanthine / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D012739:Gonadal Steroid Hormones; D009022:Morphine Derivatives; D019820:Xanthine; D002220:Carbamazepine; D009538:Nicotine
keywords: Complex mixtures; High-throughput analysis; Method development; Supercritical fluid chromatography; Ultra high performance liquid chromatography