title: Mass spectrometric analysis of carisoprodol and meprobamate in rat brain microdialysates.
abstract: We report the evaluation of several mass spectrometry-based methods for the determination of carisoprodol and meprobamate in samples obtained from the rat brain by in vivo intracranial microdialyis. Among the techniques that aspire to perform analyses without chromatographic separation and thereby increase throughput, chip-based nanoelectrospray ionization and the use of an atmospheric pressure solids analysis probe fell short of requirements because of insufficient detection sensitivity and hard ionization, respectively. Although direct analysis in real time provided the required soft ionization, shortcomings of a tandem mass spectrometry-based assay also included inadequate detection sensitivity and, in addition, poor quantitative reproducibility. Therefore, liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry was developed to determine carisoprodol and meprobamate from artificial cerebrospinal fluid as the medium. No desalting and/or extraction of the samples was necessary. The assay, combined with in vivo sampling via intracranial microdialyis, afforded time-resolved concentration profiles for the drug and its major metabolite from the nucleus accumbens region of the brain in rats after systemic administration of carisoprodol. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA. Laszlo.Prokai@unthsc.edu.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Prokai
authors.affiliation: Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA.|Present address: Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Palacky University in Olomouc, Olomouc, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Fryčák
authors.affiliation: Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA.
authors.forename: Vien
authors.initials: V
authors.lastname: Nguyen
authors.affiliation: Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Forster
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002328:Carisoprodol / Q000134:cerebrospinal fluid / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008297:Male; D008620:Meprobamate / Q000134:cerebrospinal fluid / Q000378:metabolism*; D017551:Microdialysis; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D002328:Carisoprodol; D008620:Meprobamate
keywords: LC-MS/MS; atmospheric pressure chemical ionization; atmospheric pressure solids analysis probe; carisoprodol; direct analysis in real time; in vivo intracranial microdialysis; meprobamate; nanoelectrospray ionization