A robust LC–MS/MS method for the simultaneous determination of docetaxel and voriconazole in rat plasma and its application to pharmacokinetic studies

Opportunistic fungal infections are common in immunocompromised cancer patients, especially patients undergoing chemotherapy. Because antitumor agents are possible to combine with antifungal agents in clinical, it is necessary to study drug–drug interaction between antitumor agents and antifungal agents. The aim of the study was to explore a method for the simultaneous determination of voriconazole and docetaxel in plasma and investigate pharmacokinetic interaction of voriconazole and docetaxel in rats. A precise and reliable method using liquid chromatography tandem mass spectrometry (LC–MS/MS) was established for the simultaneous measure of docetaxel and voriconazole in rat plasma after liquid–liquid extraction with ethyl acetate. The method was fully validated and successfully applied to a pharmacokinetic interaction study of docetaxel and voriconazole in rats after single or combined administration. We found that the AUC of each drug after coadministration increased compared with that after the single administration, which might be caused by interaction at the absorption stage or the competitive inhibition on the metabolic enzymes. This established method can be utilized to study the detailed mechanism of the drug–drug interaction and guide rational drug use in the clinic.     

A rapid MCM‐41 dispersive micro‐solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids

A rapid dispersive micro‐solid phase extraction (D‐μ‐SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM‐41 was used as sorbent in d ‐μ‐SPE of the azole compounds from biological fluids. Important D‐μ‐SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB‐C₁₈ column (2.1 × 100 mm, 3.5 μm), using a mobile phase of acetonitrile–0.05% formic acid in 5 mm ammonium acetate buffer (70:30, v /v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1–10,000 μg/L with satisfactory limit of detection (≤0.06 μg/L) and limit of quantitation (≤0.3 μg/L). The proposed method also showed acceptable intra‐ and inter‐day precisions for ketoconazole and voriconazole from urine and human plasma with RSD ≤16.5% and good relative recoveries in the range 84.3–114.8%. The MCM‐41‐D‐μ‐SPE method proved to be rapid and simple and requires a small volume of organic solvent (200 μL); thus it is advantageous for routine drug analysis.     

Determination and Characterization of the Uptake of Voriconazole in Human Lung Epithelial Cells by High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Voriconazole is used to prevent invasive pulmonary aspergillosis. However, little is known about the concentrations of voriconazole in human lung epithelial cells (A549), which is the target for preventing invasive pulmonary aspergillosis. The goal of this study was to develop a high-performance liquid chromatography–tandem mass spectrometry method to quantify voriconazole in A549 cells. A triple-quadrupole mass spectrometer in selected reaction monitoring mode was used with positive electrospray ionization. The total duration of each run was 5?min. The calibration curves fit a least squares model for the voriconazole concentration ranging from 0.625 to 160?ng/mL. Intraday and interday coefficients of variation were less than 10%. Recoveries at the concentrations of the quality control samples where greater than 85%, and the matrix effects showed that the ratios of the peak response exhibited a 15% suppression of the signal in the matrix compared to water. Voriconazole may penetrate A549 cells. However, the voriconazole uptake was slow in A549 cells, reaching a plateau at 2?h, where the dose-dependent intracellular voriconazole concentrations were 1.98?±?0.38, 4.43?±?0.54, and 8.14?±?0.52?ng/mg protein for extracellular voriconazole concentrations of 5, 10, and 20?µg/mL, respectively. The uptake of voriconazole by A549 cells was linear at extracellular concentrations from 0 to 20?µg/mL. This study established a rapid and sensitive method suitable for determining voriconazole in A549 cells and described the kinetic properties of the absorption of voriconazole by A549 cells.     

UPLC–MS/MS method for the determination of voriconazole plasma concentration from pediatric patients with hematologic tumors: An application toward personalized therapy

Untreated invasive fungal infection is one of the important risk factors affecting the prognosis of pediatric patients with hematologic tumors. Voriconazole (VOR) is the first-line antifungal drug for the treatment of Aspergillus infections. In order to reduce the risk of adverse drug reactions while producing an ideal antifungal effect, therapeutic drug monitoring was performed to maintain the VOR plasma concentration in a range of 1,000–5,500 ng/ml. In the present study, a reliable, accurate, sensitive and quick ultra-high performance liquid chromatograph–tandem mass spectrometry (UPLC–MS/MS) method was developed for the determination of the VOR level. Protein precipitation was performed using acetonitrile, and then the chromatographic separation was carried out by UPLC using a C₁₈ column with the gradient mobile phases comprising 0.1% methanoic acid in acetonitrile (A) and 0.1% methanoic acid in water (B). In the selective reaction monitor mode, the mass spectrometric detection was carried out using an TSQ Endura triple quadruple mass spectrometer. The performance of this UPLC–MS/MS method was validated as per the National Medical Products Administration for Bioanalytical Method Validation. Additionally, the plasma concentrations of VOR in pediatric patients with hematologic tumors were detected using this method, and the analyzed results were used for personalized therapy.     

Complexation of Voriconazole Stereoisomers with Neutral and Anionic Derivatised Cyclodextrins

A number of native, neutral derivatised and anionicderivatised cyclodextrins (CDs) were examined aschiral electrolyte additives in capillaryelectrophoresis (CE) to separate the fourstereoisomers of the new antifungal agent,voriconazole. A very large difference in interactionbetween each diastereoisomer and the CDs was observedin the CE study, where enantioselectivity was easilyobtained for one and extremely difficult to obtain forthe other. Nuclear magnetic resonance spectroscopy(¹H-NMR) indicated a strong interaction betweenthe easily separated diastereoisomer and each of theCDs with enantiomeric shift nonequivalence values ofover 100 Hz obtained when using the anionicsulphobutylether--CD chiral solvating agent. Inaccordance with observations from the CE study, theopposite diastereoisomer indicated no shiftnonequivalence at all. The nature of the complexationbetween the easily separated diastereoisomer and theanionic sulphobutylether-CD was also probedusing a two-dimensional nuclear Overhauser enhancementexperiment and a series of spin lattice relaxationtime measurements. It was found that theenantioselective interaction occurred through thepartial inclusion of a difluorophenyl group into theCD toroid which was also aided through a number ofadditional interactions between the drug molecule andthe sulphobutylether derivatives outside the CDtoroid.     

UPLC‐MS/MS determination of voriconazole in human plasma and its application to a pharmacokinetic study

A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was developed to determine voriconazole in human plasma. Sample preparation was accomplished through a simple one‐step protein precipitation with methanol. Chromatographic separation was carried out on an Acquity UPLC BEH C₁₈ column using an isocratic mobile phase system composed of acetonitrile and water containing 1% formic acid (45:55, v/v) at a flow rate of 0.50 mL/min. Mass spectrometric analysis was performed using a QTrap5500 mass spectrometer coupled with an electrospray ionization source in the positive ion mode. The multiple reaction monitoring transitions of m/z 351.0 → 281.5 and m/z 237.1 → 194.2 were used to quantify voriconazole and carbamazepine (internal standard), respectively. The linearity of this method was found to be within the concentration range of 2.0–1000 ng/mL with a lower limit of quantification of 2.0 ng/mL. Only 1.0 min was needed for an analytical run. This fully validated method was successfully applied to the pharmacokinetic study after oral administration of 200 mg voriconazole to 20 Chinese healthy male volunteers. Copyright © 2014 John Wiley & Sons, Ltd.     

Development and validation of an LC-MS/MS method for simultaneous quantification of voriconazole and its main metabolite voriconazole N-oxide in human plasma and its clinical application

An LC-MS/MS method was developed for simultaneous determination of voriconazole and its main metabolite voriconazole N-oxide in human plasma. Plasma pretreatment was simple one-step protein precipitation with acetonitrile, and separation was achieved on a Hypersil GOLD aQ column. A triple-quadrupole tandem mass spectrometer with electrospray ionization source was operated by multiple reaction monitoring (MRM) in positive ion mode, and the precursor–product ion pairs used for MRM were m/z 350.1→281.0, 365.8→224.1, and 531.3→489.2 for voriconazole, voriconazole N-oxide, and internal standard, respectively. The total analytical run time was 6?min. The proposed method was linear over the range 0.001–1?µg/mL for voriconazole and voriconazole N-oxide. The lower limit of quantification was 1?ng/mL for both of them. The specificity, accuracy, precision, recovery, matrix effect, stability as well as dilution integrity of this method were within acceptable limits during validation period. This method was successfully applied to therapeutic drug monitoring of voriconazole and to evaluate its metabolite profile.     

Direct injection HPLC micro method for the determination of voriconazole in plasma using an internal surface reversed-phase column

A direct plasma injection liquid chromatographic method has been developed for the determination of a new triazole antifungal agent, voriconazole, using an internal surface reversed phase column. Therapeutic drug monitoring of voriconazole is relevant for patient management, especially in the case of drug-drug interaction. The method is easy to perform and requires 10 microL of a plasma sample. The chromatographic run time is less than 9 min using a mobile phase of 17:83 v/v acetonitrile-potassium dihydrogen phosphate buffer, 100 mM, pH 6.0 and UV detection at 255 nm. The fl ow rate was 1 microL/min. A linear response was observed over the concentration range 0.5-10 microg/mL (r2 = 0.977). A good accuracy (bias < or = 7.5%) was achieved for all quality controls, with intra-day and inter-day variation coefficients inferior to 6.7%. The lower limit of quantitation was 0.2 microg/mL, without interference of endogenous components. The stability of voriconazole in plasma stored at different temperatures was checked. Finally, the possibility of direct injection of plasma samples into the column permits a reduction in reagent consumption and in analytical steps, and hence in analytical error.