title: A new, high-throughput high-performance liquid chromatographic/mass spectrometric assay for therapeutic level monitoring of digoxin in human plasma.
abstract: A new, high-throughput HPLCIMS assay for the quantification of digoxin in human plasma was developed and validated. The separation was performed on a Zorbax SB-C18 column under isocratic conditions using a 55 + 45 (v/v) mixture of methanol and 0.1% (v/v) formic acid in 10 microM sodium acetate as the mobile phase at 45 degrees C with a flow rate of 1 mL/min. The detection of digoxin was performed in the selected ion monitoring mode (m/z 803.5). The human plasma samples (0.2 mL) were deproteinized with 7% perchloric acid in water, and aliquots of 20 microL from supernatants obtained after centrifugation were directly injected into the chromatographic system. The method showed good linearity (r > 0.9926), precision (CV > 18.9%), and accuracy (bias > 5.6%) over the range of 0.5-50 ng/mL plasma. The lower LOQ was 0.5 ng/mL, and the recovery was between 92 and 106%. The method is not expensive, it needs a minimum time for plasma sample preparation, and it has a run time of 2.3 min for instrument analysis (the retention time of digoxin was 1.9 min). The developed and validated high-throughput method is very simple, rapid, and efficient, with wide applications in clinical level monitoring, pharmacokinetics, and bioequivalence studies.
authors.affiliation: Iuliu Hatieganu"University of Medicine and Pharmacy, Department of Pharmaceutical Technology and Biopharmacy, Faculty of Pharmacy, Emil Isac 13, RO-400023, Cluj-Napoca, Romania.
authors.forename: Laurian
authors.initials: L
authors.lastname: Vlase
authors.forename: Daniela-Saveta
authors.initials: DS
authors.lastname: Popa
authors.forename: Dana
authors.initials: D
authors.lastname: Muntean
authors.forename: Dan
authors.initials: D
authors.lastname: Mihu
authors.forename: Sorin
authors.initials: S
authors.lastname: Leucuta
mesh_terms: D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004077:Digoxin / Q000032:analysis* / Q000737:chemistry; D016903:Drug Monitoring / Q000379:methods; D004355:Drug Stability; D005561:Formates / Q000032:analysis; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D010472:Perchlorates / Q000032:analysis; D010949:Plasma / Q000378:metabolism*; D012015:Reference Standards; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors
chemical_list: D005561:Formates; D010472:Perchlorates; C030544:formic acid; D004077:Digoxin; D000432:Methanol