Determination of lovastatin in human plasma by ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry and its application in a pharmacokinetic study

A selective, rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the quantitative determination of lovastatin in human plasma and its application in a pharmacokinetic study. With mycophenolate mofetil as internal standard, sample pretreatment involved a one-step extraction with tert-butyl methyl ether of 0.2 ml plasma. The analysis was carried out on an ACQUITY UPLCTM BEH C18 column (50 mm x 2.1 mm, i.d., 1.7 microm) with flow rate of 0.35 ml/min. The mobile phase was 20% water and 80% acetonitrile (v/v). The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI). Linear calibration curves were obtained in the concentration range of 0.08-24.50 ng/ml, with a lower limit of quantification of 0.08 ng/ml. The intra- and inter-day precision (RSD) values were below 15% and accuracy (RE) was -7.6 to 9.3% at all QC levels. The method was applicable to clinical pharmacokinetic study of lovastatin in healthy volunteers following oral administration.     

Determination of nimodipine in human plasma by ultra performance liquid chromatography-tandem mass spectrometry and pharmacokinetic application

A fast and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination and pharmacokinetic study of nimodipine in human plasma. With nitrendipine as the internal standard, sample pretreatment involved one-step extraction with diethyl ether of 0.5 ml plasma. The separation was carried out on an ACQUITY UPLC BEH C(18) column (50 mm x 2.1 mm, i.d., 1.7 microm) with water and acetonitrile (both containing 0.1% formic acid) as the mobile phase under gradient conditions at a flow rate of 0.35 ml/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The standard curves were linear (r(2)> or =0.99) over the concentration range of 0.20-100 ng/ml with a limit of quantification (LLOQ) of 0.20 ng/ml. The intra- and inter-day precision (R.S.D.) values were below 14% and the accuracy (relative error R.E.) was ranged from -2.2% to 7.7% at all three quality control (QC) levels. The method herein described was superior to previous methods and successfully applied to the pharmacokinetic study of nimodipine tablets in healthy male volunteers after oral administration.     

Development and full validation of a sensitive quantitative assay for the determination of clemastine in human plasma by liquid chromatography-tandem mass spectrometry

A sensitive high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of clemastine in human plasma. After having been extracted from plasma samples by ethyl acetate, clemastine and internal standard, diphenhydramine, were separated on a C(18) column. Detection was performed on Thermo Finnigan TSQ Quantum triple quadrupole mass spectrometer by selected reaction monitoring (SRM) mode via electrospray ionization (ESI) source. The method was linear in the concentration range of 5.0-1000.0 pg/ml for clemastine. The intra- and inter-day precisions were within 13.4% and the deviations were between -1.1% and 5.6%. The fully validated LC/ESI-MS/MS method has been successfully applied to the preliminary pharmacokinetic study in healthy male Chinese volunteers.     

Determination of chamaechromone in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetic study

A rapid, simple and accurate method was developed for the determination of chamaechromone in rat plasma using liquid chromatography tandem mass spectrometry (LC–MS–MS). Rosuvastatin was used as the internal standard. The plasma samples were extracted by liquid–liquid extraction with ethyl acetate. Chromatographic separation was performed on Xbridge™ C₁₈ column (2.1 mm × 50 mm, 3.5 μm) with linear gradient elution using water and methanol, both of which were acidified with 0.1% aqueous formic acid. The flow rate was 0.4 mL/min and the total run time was 6 min. Detection was performed on a triple-quadrupole tandem mass spectrometer using positive ion mode electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 543.3 → 198.9 and 481.9 → 258.3 for chamaechromone and rosuvastatin, respectively. Good linearity was observed over the concentration range of 8–6400 ng/mL in 0.1 mL of rat plasma. The lowest concentration (8 ng/mL) in the calibration curve was estimated as LLOQ with both deviation of accuracy and RSD of precision <20% (n = 6). Intra-assay and inter-assay variability were less than 11% in plasma. This method was successfully applied to a pharmacokinetic study of chamaechromone in rats after intravenous (5 mg/kg) and oral (100 mg/kg) administration. Following oral administration the concentration–time curve of chamaechromone exhibited a biphasic absorption profile. The maximum mean concentration in plasma (C_max, 795.9 ± 14.6 ng/L) was achieved at 11.3 ± 0.8 h (T_max) and the area under curve (AUC_0–60) was 6976.7 ± 1026.9 ng h/L. After single intravenously administration of chamaechromone, the essential pharmacokinetic parameters C_max, AUC_0–48 were 4300.7 ± 113.6 ng/L and 3672.1 ± 225.4 ng h/L, respectively. The result showed that the compound was poorly absorbed with an absolute bioavailability being approximately 8.9%.     

High-performance liquid chromatography-electrospray ionization mass spectrometry determination of sodium ferulate in human plasma

A selective and sensitive high-performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for the determination of sodium ferulate in human plasma. The sample preparation was a liquid-liquid extraction and chromatographic separation was achieved with an Agilent ZORBAX SB-C(18) (3.5 microm, 100 mm x 3.0 mm) column, using a mobile phase of methanol-0.05% acetic acid 40:60 (v/v). Standard curves were linear (r(2)=0.9982) over the concentration range of 0.007-4.63 nM/ml and had acceptable accuracy and precision. The within- and between-batch precisions were within 12% relative standard deviation. The lower limit of quantification (LLOQ) was 0.007 nM/ml. The validated HPLC-ESI-MS method has been used successfully to study sodium ferulate pharmacokinetics, bioavailability and bioequivalence in 20 healthy volunteers.     

Determination and pharmacokinetic study of amlodipine in human plasma by ultra performance liquid chromatography-electrospray ionization mass spectrometry

A novel, specific and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination and pharmacokinetic study of amlodipine in human plasma. The analysis was carried out on an ACQUITY UPLC BEH C(18) column (50 mm x 2.1 mm, i.d., 1.7 microm) with gradient elution at a flow-rate of 0.35 ml/min. The mobile phase was water and acetonitrile under gradient conditions (both containing 0.3% formic acid) and nimodipine was used as the internal standard. Detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via Turbo ion spray ionization (ESI). Linear calibration curves were obtained over the concentration range 0.15-16.0 ng/ml, with a lower limit of quantification of 0.15 ng/ml. The intra- and inter-day precision (R.S.D.) values were below 15% and the accuracy (R.E.) was -2.3% to 6.9% at all three QC levels. The method was used to support clinical pharmacokinetic studies of amlodipine in healthy volunteers following oral administration.     

高效液相色谱-质谱-质谱联用法测定人血浆中艾司西酞普兰浓度及其药代动力学研究

目的建立测定人血浆中艾司西酞普兰浓度的高效液相色谱-质谱-质谱联用法.方法血浆样品经甲醇沉淀后进行分析.色谱柱Lichrospher CN柱150 mm×4.6 m I.D.5μm,流动相甲醇水(含15 mmol·L-1乙酸铵)甲酸(72∶28O.1,v/v/v),流速1.0ml·min-1,电喷雾离子化三重四极杆串联质谱检测,以选择离子反应监测(SRM)扫描方式进行检测,采用选择离子反应监测(SRM)方式进行定量分析,用于监测的离子为m/z 325.0→234.0(西酞普兰)和m/z 409.1→238.1(氨氯地平,内标).结果线性范围为0.20～50.00ng·ml-1,最低定量浓度为0.20 ng·ml-1,应用此法测试了10名健康受试者口服草酸艾司西酞普兰片(10 mg)后不同时间的血药浓度,得到艾司西酞普兰药动学参数,Cmax为9.21±2.10 ng·ml-1,Tmax为3.75±1.04h,AUC0-t为514.6±152.3 ng·h·ml-1,AUC0-∞为540.5±162.3 ng·h·ml-1,t1/2为34.06±7.71 h及Ke为0.021±O.004h-1.结论该法专属、灵敏、简便、快速,适用于人血浆中艾司西酞普兰浓度的测定.     

Quantification of oltipraz using liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study in rat plasma

An assay method for the determination of oltipraz, a candidate drug for the treatment of liver fibrosis and liver cirrhosis, was developed in rat plasma using a fast-flow protein precipitation (FF-PPT) method coupled with LC-MS/MS for quantification to reduce the labor and to improve the speed of analysis. The applicability of the assay to pharmacokinetic studies was also evaluated. Oltipraz and ethyl-oltipraz, an internal standard (IS), were analyzed by multiple reaction monitoring (MRM) at m/z transitions of 227 → 193 and 241 → 174, respectively. A lower limit of quantification (LLOQ) of 20 ng/mL was observed, with a linear dynamic range from 20 to 4000 ng/mL (R > 0.997). The accuracy, precision, dilution, recovery, and stability of the assay were deemed acceptable according to FDA guidelines. Oltipraz concentrations were measured successfully in plasma samples up to 12 h post-dose in rats that had received an oral dose of 60 mg/kg. The findings indicate that the assay method is rapid and sensitive to oltipraz, showing applicability for pharmacokinetics (PK) studies of oltipraz in other small animals, including rats.     

LC-ESI-MS/MS法测定人血浆中卢帕他定的浓度（英文）

目的建立测定人血浆中卢帕他定浓度的LC-ESI-MS/MS方法。方法血浆样品加入内标,碱化后用二氯甲烷：乙酸乙酯（20：80）提取,在37℃真空干燥箱中干燥至干,残渣用200μL流动相溶解后进样。色谱条件为：色谱柱为Agilent Eclipse XDB-C18（4.6mm×150mm,5μL）;流动相为乙腈（含1%甲酸）：20mmol·L^-1醋酸铵（76：24,V/V）,流速为0.6mL·min^-1。质谱条件：采用美国安捷仑1100高效液相色谱系统和离子阱（Agilent MSD Trap XCT）检测仪,质谱条件为电喷雾离子源,检测方式为正离子电离、多离子反应监测（MRM）,用于定量分析的离子为卢帕他定m/z416→309,内标氯雷他定m/z383→337。结果该方法应用于检测20名健康志愿者服药后的血浆样品。线性范围为0.05～14ng·mL^-1（r=0.998）,日内和日间精密度均低于15%,方法回收率为85.1%～114.0%。最低检测限为0.05ng·mL^-1（当n=5时,RSD=9.22%）。结论该方法灵敏、准确、快速,可用于该药药代动力学和生物等效性研究。     

LC/MS/MS法测定人血浆中头孢克肟含量

目的 建立人血浆中头孢克肟的LC/MS/MS法.方法 血浆样品经蛋白沉淀提取,采用C8色谱柱分析,以乙腈:水:甲酸(40:60:0.5,v/v/v)为流动相,三重四级杆质谱检测器,正离子多反应监测模式(MRM),监测离子分别为:m/z 454.3→m/z 285.2(头孢克肟),m/z 282.2→m/z 212.2(...     

An HPLC-MS/MS method for the quantitative determination of 4-hydroxy-anethole trithione in human plasma and its application to a pharmacokinetic study

A selective, rapid and sensitive method for the quantitation of 4-hydroxy-anethole trithione (ATX) in human plasma based on high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) was developed and validated. Paracetamol was used as the internal standard (I.S.). After liquid–liquid extraction of 500 μL plasma with ethyl acetate, ATX and the I.S. were chromatographed on an Inertsil^® ODS-3 column. The mobile phase was consisted of methanol–water (75:25, v/v) with a flow rate of 0.25 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The calibration curve was linear over the range of 0.452–603 ng/mL (r² ≥ 0.99) with a lower limit of quantitation (LLOQ) of 0.452 ng/mL. The intra- and inter-day precision (relative standard deviation, R.S.D.) values were below 13% and the accuracy (relative error, R.E.) was from −2.7% to −7.5% at three quality control levels. The assay herein described was successfully applied to a pharmacokinetic study of anethole trithione (ATT) tablet in healthy volunteers after oral administration.     

Hydrophilic interaction chromatography-tandem mass spectrometry of donepezil in human plasma: Application to a pharmacokinetic study of donepezil in volunteers

A selective, sensitive and rapid hydrophilic interaction liquid chromatography with electrospray ionization tandem mass spectrometry was developed for the determination of donepezil in human plasma. Donepezil was twice extracted from human plasma using methyl tert-butyl ether at basic pH. The analytes were separated on an Atlantis HILIC Silica column with the mobile phase of acetonitrile: ammonium formate (50 mM, pH 4.0) (85:15, v/v) and detected by tandem mass spectrometry in the selective reaction monitoring mode. The calibration curve was linear (r = 0.9994) over the concentration range of 0.10-50.0 ng/mL and the lower limit of quantification was 0.1 ng/mL using 200 muL plasma sample. The coefficient of variation and relative error for intra-and inter-assay at four QC levels were 2.7 to 10.5% and -10.0 to 0.0%, respectively. There was no matrix effect for donepezil and cisapride. The present method was successfully applied to the pharmacokinetic study of donepezil after oral dose of donepezil hydrochloride (10 mg tablet) to male healthy volunteers.     

Determination of tiapride in human plasma using hydrophilic interaction liquid chromatography-tandem mass spectrometry

A rapid, sensitive and selective hydrophilic interaction liquid chromatography-tandem mass spectrometric (HILIC-MS/MS) method for the determination of tiapride in human plasma was developed. Tiapride and internal standard, metoclopramide were extracted from human plasma with dichloromethane at basic pH and analyzed on an Atlantis HILIC silica column with the mobile phase of acetonitrile-ammonium formate (190 mM, pH 3.0) (94:6, v/v). The analytes were detected using an electrospray ionization tandem mass spectrometry in the multiple-reaction-monitoring mode. The standard curve was linear (r=0.999) over the concentration range of 1.00-200 ng/mL. The coefficient of variation and relative error for intra- and interassay at three QC levels were 6.4-8.8% and -2.0-3.6%, respectively. The recoveries of tiapride ranged from 96.3 to 97.4%, with that of metoclopramide (internal standard) being 94.2%. The lower limit of quantification for tiapride was 1.00 ng/mL using 100 microL of plasma sample.     

Establishment of a liquid chromatographic/mass spectrometry method for quantification of tetrandrine in rat plasma and its application to pharmacokinetic study

A rapid and sensitive liquid chromatography-tandem mass spectrometric method (LC/MS/MS) for the determination of tetrandrine in rat plasma has been developed, fully validated and successfully applied to pharmacokinetic study in Sprague-Dawley (SD) rats after a single oral administration. Sample preparation involves a liquid-liquid extraction with n-hexane-dichlormethane (65:35, containing 1% 2-propanol isopropyl alcohol, v/v). Tetrandrine and brodimoprim (internal standard) were well separated by LC with a Dikma C(18) column using acetonitrile-methanol-ammonium formate aqueous solution (20mM) containing 0.3% formic acid (20:30:50, v/v/v) as mobile phase. Detection was performed on a triple quadrupole mass spectrometer in multiple reaction monitoring mode. The ionization was optimized using ESI(+) and selectivity was achieved using MS/MS analysis, m/z 623.0-->381.0 and m/z 339.0-->281.0 for tetrandrine and I.S., respectively. The present method exhibited good linearity over the concentration range of 5-2,000 ng/mL for tetrandrine in rat plasma with a lower limit of quantification of 5 ng/mL. The intra- and inter-day precision were 2.0-9.2% and 4.5-9.4%, and the intra- and inter-day accuracy ranged from -7.6 to 10.3% and -6.0 to 5.3%, respectively. No endogenous compounds were found to interfere with the analysis, and tetrandrine was stable during the whole assay period. The method was successfully applied to a pharmacokinetic study after an intragastric administration (i.g.) of tetrandrine to SD rats with a single dose of 50mg/kg. The results confirm that the assay is suitable for the pharmacokinetic study of tetrandrine.     

LC-MS/MS测定人血浆米格列奈浓度及药代动力学研究

目的:建立人血浆中米格列奈浓度的LC-MS/MS检测方法,研究米格列奈钙片单次及连续给药后在健康人体内的药代动力学。方法:应用建立的LC-MS/MS法测定人血浆米格列奈浓度,以DAS软件计算主要药代动力学参数。结果:健康受试者单次给药5,10,20 mg主要药代动力学参数:Cmax为(435.3±182.5),(811.7±276.0)和(1 549.8±353.2)μg.L-1;Tmax为(0.642±0.61),(0.508±0.29)和(0.5±0.167)h;t1/2为(1.445±0.146),(1.343±0.215)和(1.404±0.209)h;AUC0~t为(725.7±154.8),(1 504.3±285.3)和(2 784.9±554.0)μg.L-1.h。连续给药10 mg主要药代动力学参数:Cmax为(1 005.7±338.0)μg.L-1;Tmax为(0.492±0.384)h;Cmin为(40.33±20.15)μg.L-1;t1/2为(1.670±0.363)h;AUCss为(1 645.2±469.1)μg.L-1.h;Cav为(205.6±58.64)μg.L-1;DF...     

Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of zofenopril and its active metabolite zofenoprilat in human plasma

A novel, sensitive and rapid liquid chromatographic-electrospray ionization mass spectrometric method was developed and validated for the determination of zofenopril and its active metabolite zofenoprilat in human plasma. The method was based on a single extraction step using methyl tert-butyl ether and did not require chemical derivatization. The chromatographic conditions were optimized; separation was performed on a phenyl-hexyl column (5μm, 250mm×4.6mm i.d.) with a mobile phase consisting of a solution of methanol and water (95:5, v/v) that also contained 0.1% of formic acid. A flow rate of 1.0mL/min was used. Zofenopril, zofenoprilat and the internal standard (IS) fosinopril sodium were measured using an electrospray ion source in a positive reaction monitoring mode. Linear calibration curves were generated for zofenopril concentrations between 0.1052 and 1052ng/mL and for zofenoprilat concentrations between 0.2508 and 2508ng/mL. In both cases, the coefficients of determination were greater than 0.995. The extraction recovery for zofenopril was 93.5% on average. It was 92.5% for zofenoprilat. The inter- and intra-batch precision and accuracy for both zofenopril and zofenoprilat were higher than 14%. The method was applied to measure the concentrations of zofenopril and zofenoprilat in plasma samples.     

Determination of diethylstilbestrol in human plasma using high performance liquid chromatography-tandem mass spectrometry

A sensitive, fast, and reproducible high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of diethylstilbestrol in human plasma was developed and validated. The plasma samples were pretreated by direct deproteinization with ethyl acetate. Daidzein was used as the internal standard. The separation was carried out on a Agilent Technologies 1200 series XDB C₁₈ column (2.1 mm×150 mm, 5 µm) with a mobile phase of acetonitrile-2.5 mmol/L ammonium acetate (60:40, v/v). Triple quadrupole mass spectrometric detection in negative ion mode was used for multiple-reaction-monitoring of the transitions atm/z 267.2→237.3 and m/z 253.2→132.3 for diethylstilbestrol and daidzein, respectively.The calibration curves were linear over the concentration range from 0.1 to 20 ng/mL (r² = 0.9984). The lower limit of quantificationwas 0.1 ng/mL (s/n mLs)for diethylstilbestrol, which was sensitive enough to perform pharmacokinetic studies after diethylstilbestroladministration. Inter-day and intra-day precisions were no more than 7% with accuracies of 90%-105%. This method could be applied to therapeutic drug monitoring of diethylstilbestrol, which is helpful for evaluating the clinical efficacy and safety of diethylstilbestrol.     

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of tenofovir and emtricitabine in human plasma and its application to a bioequivalence study

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for simultaneous quantification of Tenofovir (TEN) and Emtricitabine (EMT) in human plasma using Chromolith Speed Rod RP18. The mass transition ion-pair has been followed as m/z 288.10-->176.10 for TEN, m/z 248.20-->130.20 for EMT and m/z 230.10-->112.10 for Lamivudine (LAM). The method involves solid phase extraction from plasma, simple isocratic chromatographic conditions and mass spectrometric detection using an API 5000 instrument that enables detection at nanogram levels. Lamivudine was used as the internal standard. The proposed method has been validated with a linear range of 10-600 ng/ml for TEN and 25-2,500 ng/ml for EMT. The intrarun and interrun precision values are within 12.0% for TEN and 15.6% for EMT at their respective LOQ levels. The overall recoveries for TEN and EMT were 84.3% and 68.5%, respectively. Total elution time was as low as 2 min.     

Quantitative determination of spinosin in rat plasma by liquid chromatography-tandem mass spectrometry method

A sensitive method for the quantitative determination of spinosin in rat plasma was developed and validated using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The analytes of interest were extracted from rat plasma samples by methyl tert-butyl ether (MTBE) after acidification with 1.0% acetic acid aqueous solution. Chromatographic separation was achieved on an Agilent Zorbax SB-C(18) (50 mm x 4.6 mm, 5 microm) using a isocratic mobile phase consisting of acetonitrile-water (30:70, v/v) with 1% isopropyl alcohol and 0.01% heptafluorobutyric acid. The flow rate was 0.2 ml/min. The column temperature was maintained at 25 degrees C. Detection was performed on a triple quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) mode via electrospray ionization (ESI). The calibration curve was linear over the range of 1.00-400 ng/ml in rat plasma, with 1.00 ng/ml of the lower limit of quantification (LLOQ). The inter- and intra-day precisions and accuracy for all samples were satisfactory. The validated method was successfully applied for the pharmacokinetic study of spinosin in rat. After oral administration of 20mg/kg spinosin to rats, the main pharmacokinetic parameters of T(max), C(max), T(0.5) and AUC(0-T) were 5.33+/-0.58 h, 132.2+/-10.6 ng/ml, 4.89+/-0.37 h, 1.02+/-0.09 microg h/l, respectively.