title: Systematic approach to optimize a pretreatment method for ultrasensitive liquid chromatography with tandem mass spectrometry analysis of multiple target compounds in biological samples.
abstract: In current approaches for new drug development, highly sensitive and robust analytical methods for the determination of test compounds in biological samples are essential. These analytical methods should be optimized for every target compound. However, for biological samples that contain multiple compounds as new drug candidates obtained by cassette dosing tests, it would be preferable to develop a single method that allows the determination of all compounds at once. This study aims to establish a systematic approach that enables a selection of the most appropriate pretreatment method for multiple target compounds without the use of their chemical information. We investigated the retention times of 27 known compounds under different mobile phase conditions and determined the required pretreatment of human plasma samples using several solid-phase and liquid-liquid extractions. From the relationship between retention time and recovery in a principal component analysis, appropriate pretreatments were categorized into several types. Based on the category, we have optimized a pretreatment method for the identification of three calcium channel blockers in human plasma. Plasma concentrations of these drugs in a cassette-dose clinical study at microdose level were successfully determined with a lower limit of quantitation of 0.2 pg/mL for diltiazem, 1 pg/mL for nicardipine, and 2 pg/mL for nifedipine.
authors.affiliation: Pharmaceutical Division, Sumika Chemical Analysis Service Ltd, Osaka, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Togashi
authors.affiliation: Pharmaceutical Division, Sumika Chemical Analysis Service Ltd, Osaka, Japan.
authors.forename: Kuninori
authors.initials: K
authors.lastname: Mutaguchi
authors.affiliation: Pharmaceutical Division, Sumika Chemical Analysis Service Ltd, Osaka, Japan.
authors.forename: Setsuko
authors.initials: S
authors.lastname: Komuro
authors.affiliation: Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kataoka
authors.affiliation: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
authors.affiliation: Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamashita
mesh_terms: D002121:Calcium Channel Blockers / Q000097:blood* / Q000302:isolation & purification*; D002853:Chromatography, Liquid / Q000379:methods; D006801:Humans; D059625:Liquid-Liquid Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D002121:Calcium Channel Blockers
keywords: Biological samples; Liquid chromatography with tandem mass spectrometry; Method development; Microdoses; Sample pretreatment