title: Highly specific and sensitive liquid chromatography-tandem mass spectrometry method for the determination of 3-desmethylthiocolchicine in human plasma as analyte for the assessment of bioequivalence after oral administration of thiocolchicoside.
abstract: A sensitive method for the determination of 3-desmethylthiocolchicine in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The plasma samples were extracted with ethyl acetate and separated on a Phenomenex Luna C18(2) 5 microm, 150x2 mm column with a mobile phase consisting of acetonitrile-0.005% formic acid (350:650, v/v) at a flow rate of 0.35 ml/min. Detection was achieved by an Applied Biosystems API 2000 mass spectrometer (LC-MS-MS) set at unit resolution in the multiple reaction monitoring mode. TurbolonSpray ionisation was used for ion production. The mean recovery for 3-desmethylthiocolchicine was 70%, with a lower limit of quantification set at 0.39 ng/ml. The increased selectivity of mass spectrometric (MS-MS) detection allowed us to distinguish between thiocolchicoside and its primary metabolite 3-desmethylthiocolchicine in human plasma, thereby giving more insight about the pharmacokinetics of the drug in humans.
authors: Farmovs-Parexel Clinical Research Organisation, Brandhof, Bloemfontein, South Africa. chris.sutherland@farmovs-parexel.com
authors: F C W
authors: FC
authors: Sutherland
authors: M J
authors: MJ
authors: Smit
authors: L
authors: L
authors: Herbst
authors: J
authors: J
authors: Els
authors: H K L
authors: HK
authors: Hundt
authors: K J
authors: KJ
authors: Swart
authors: A F
authors: AF
authors: Hundt
mesh_terms: D000284:Administration, Oral; D002853:Chromatography, Liquid / Q000379:methods*; D003078:Colchicine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood* / Q000493:pharmacokinetics; D018755:GABA Agonists / Q000097:blood* / Q000493:pharmacokinetics; D006207:Half-Life; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: C467079:3-desmethylthiocolchicine; D018755:GABA Agonists; D003078:Colchicine; C004280:thiocolchicoside