RESUMEN
A selective, sensitive and rapid liquid chromatography-tandem mass spectrometry method for the determination of levonorgestrel in plasma was developed. An Applied Biosystems API 3000 triple quadrupole mass spectrometer set to multiple reaction monitoring (MRM) mode, using atmospheric pressure photospray ionisation (APPI) in the positive mode. Using 17-alpha-methyltestosterone as internal standard (IS), liquid-liquid extraction was followed by reversed phase liquid chromatography using a phenyl-hexyl column and tandem mass spectrometric detection. The mean recovery for levonorgestrel and 17-alpha-methyltestosterone was 99.5 and 62.9%, respectively. The method was validated from 0.265 to 130 ng levonorgestrel/ml plasma with the lower limit of quantification (LLOQ) set at 0.265 ng/ml. This assay method makes use of the increased sensitivity and selectivity of tandem mass spectrometric (MS/MS) detection, allowing for a rapid (extraction and chromatography) and selective method for the determination of levonorgestrel in human plasma. The assay method was used in a pharmacokinetic study to quantify levonorgestrel in human plasma samples generated after administrating a single oral dose of 1.5 mg levonorgestrel to healthy female volunteers for up to five half lives. The total chromatographic runtime of this method was 5.0 min per sample, allowing for analysis of a large number of samples per batch.
Asunto(s)
Cromatografía Liquida/métodos , Anticonceptivos Femeninos/sangre , Levonorgestrel/sangre , Espectrometría de Masas/métodos , Calibración , Humanos , Estándares de Referencia , Sensibilidad y EspecificidadRESUMEN
A selective, sensitive and rapid liquid chromatography-tandem mass spectrometry method for the determination of alfuzosin in plasma was developed. A PE Sciex API 2,000 triple quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode, using TurboIonSpray with positive ionisation was used. Using prazosin as an internal standard, liquid-liquid extraction was followed by C(18) reversed-phase liquid chromatography and tandem mass spectrometry. The mean recovery for alfuzosin was 82.9% with a lower limit of quantification set at 0.298 ng/ml, the calibration range being between 0.298 and 38.1 ng/ml. This assay method makes use of the increased sensitivity and selectivity of tandem mass spectrometric (MS-MS) detection to allow for a more rapid (extraction and chromatography) and selective method for the determination of alfuzosin in human plasma than has previously been described. The assay method was used to quantify alfuzosin in human plasma samples generated in a multiple-dose (5 mg bd.) study at steady state.
Asunto(s)
Antagonistas Adrenérgicos alfa/sangre , Cromatografía Liquida/métodos , Quinazolinas/sangre , Espectrometría de Masa por Ionización de Electrospray/métodos , Antagonistas Adrenérgicos alfa/farmacocinética , Humanos , Quinazolinas/farmacocinética , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Meloxicam was quantified in human plasma after a single 15 mg oral dose of the drug was given to 26 healthy volunteers. An Applied Biosystems Sciex API 2000 triple quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode, using TurboIonSpray (TIS) in the positive ion mode, was used. Protein precipitation with acetonitrile was followed by C(18) reverse phase liquid chromatography and tandem mass spectrometry. The mean recovery for meloxicam was 92% with a lower limit of quantification of 8.96 ng/ml. Piroxicam was used as the internal standard. This assay method makes use of the increased sensitivity and selectivity of tandem mass spectrometry (MS-MS) detection to allow for a more rapid (extraction and chromatography) and selective method for the determination of meloxicam in human plasma than has previously been described.
Asunto(s)
Antiinflamatorios no Esteroideos/sangre , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Tiazinas/sangre , Tiazoles/sangre , Humanos , Meloxicam , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
A rapid and sensitive method for the determination of domperidone in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometry detection. The samples were rendered basic with 1 M Na2CO3 and the domperidone extracted using tert.-butyl methyl ether, followed by back-extraction into formic acid (2% in water). Chromatography was performed on a Phenomenex Luna C8 (2), 5 microm, 150x2 mm column with a mobile phase consisting of acetonitrile-0.02% formic acid (300:700, v/v), delivered at 0.2 ml/min. Detection was performed using an Applied Biosystems Sciex API 2000 mass spectrometer set at unit resolution in the multiple reaction monitoring mode. TurbolonSpray ionisation was used for ion production. The mean recovery of domperidone was +/- 100%, with a lower limit of quantification set at 0.189 ng/ml. This assay method makes use of the increased sensitivity and selectivity of tandem mass spectrometric detection resulting in a rapid (extraction and chromatography) and sensitive method for the determination of domperidone in human plasma, which is more sensitive than previously described methods.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Domperidona/sangre , Antagonistas de Dopamina/sangre , Espectrometría de Masa por Ionización de Electrospray/métodos , Humanos , Sensibilidad y EspecificidadRESUMEN
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.
Asunto(s)
Cromatografía Liquida/métodos , Colchicina/análogos & derivados , Colchicina/sangre , Agonistas del GABA/sangre , Espectrometría de Masa por Ionización de Electrospray/métodos , Administración Oral , Colchicina/administración & dosificación , Colchicina/farmacocinética , Agonistas del GABA/farmacocinética , Semivida , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Equivalencia TerapéuticaRESUMEN
A sensitive method for the determination of stavudine in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted from plasma with Waters, Sep-Pak Vac, 100 mg, tC(18) solid-phase extraction (SPE) columns. Chromatography was performed on a Supelco Discovery C(18), 5 microm, 150 x 2 mm column with a mobile phase consisting of ammonium acetate (0.01 M)-acetonitrile-methanol (800:100:100, v/v/v) at a flow-rate of 0.3 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 (MRM). Atmospheric pressure chemical ionization (APCI) was used for ion production. The mean recovery for stavudine was 94% with a lower limit of quantification set at 4 ng/ml. This assay method makes use of the increased sensitivity and selectivity of mass spectrometric (MS-MS) detection to allow for a more rapid (extraction and chromatography) and selective method for the determination of stavudine in human plasma than has previously been described.