Development and validation of amisulpride in human plasma by HPLC coupled with tandem mass spectrometry and its application to a pharmacokinetic study

In this study, authors developed a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantification of Amisulpride in human plasma using Amisulpride-d(5) as an internal standard (IS). Chromatographic separation was performed on Zorbax Bonus-RP C18, 4.6 × 75 mm, 3.5 μm column with an isocratic mobile phase composed of 0.2% formic acid:methanol (35:65 v/v), at a flow-rate of 0.5 mL/min. Amisulpride, Amisulpride-d(5) was detected at m/z 370.1→242.1 and 375.1→242.1. The drug and the IS were extracted by a liquid-liquid extraction method. The method was validated over a linear concentration range of 2.0-2500.0 ng/mL for Amisulpride with a correlation coefficient of (r(2)) ≥ 0.9982. This method demonstrated intra- and inter-day precision within 0.9 to 1.7 and 1.5 to 2.8 % and intra- and inter-day accuracy within 98.3 to 101.5 and 96.0 to 101.0 % for Amisulpride. Amisulpride was found to be stable at 3 freeze-thaw cycles, bench top and auto sampler stability studies. The developed method was successfully applied to a pharmacokinetic study.     

Screening of anabolic steroids in horse urine by liquid chromatography-tandem mass spectrometry

Anabolic steroids have the capability of improving athletic performance and are banned substances in the Olympic games as well as in horseracing and equestrian competitions. The control of their abuse in racehorses is traditionally performed by detecting the presence of anabolic steroids and/or their metabolite(s) in urine samples using gas chromatography–mass spectrometry (GC–MS). However, this approach usually requires tedious sample processing and chemical derivatisation steps and could be very insensitive in detecting certain steroids. This paper describes a high performance liquid chromatography–tandem mass spectrometry (HPLC–MS–MS) method for the detection of anabolic steroids that are poorly covered by GC–MS. Enzyme-treated urine was processed by solid-phase extraction (SPE) using a Bond Elut Certify^® cartridge, followed by a base wash for further cleanup. Separation of the steroids was carried out on a reversed-phase DB-8 column using 0.1% acetic acid and methanol as the mobile phase in a gradient elution programme. The mass spectrometer for the detection of the steroids was operated in the positive electrospray ionisation (ESI) mode with multiple reaction monitoring (MRM). Urine samples fortified with 15 anabolic steroids (namely, androstadienone, 1-androstenedione, bolasterone, boldione, 4-estrenedione, gestrinone, methandrostenolone, methenolone, 17-methyltestosterone, norbolethone, normethandrolone, oxandrolone, stenbolone, trenbolone and turinabol) at low ng/mL levels were consistently detected. No significant matrix interference was observed at the retention times of the targeted ion masses in blank urine samples. The method specificity, sensitivity, precision, recoveries, and the performance of the enzyme hydrolysis step were evaluated. The successful application of the method to analyse methenolone acetate administration urine samples demonstrated that the method could be effective in detecting anabolic steroids and their metabolites in horse urine.     

液相色谱串联质谱法分析血浆中美金刚浓度及其应用

目的：建立一种新的液相色谱质谱法（LC—MS／MS）,测定人血浆中关金刚的浓度。方法：血浆样品经萃取后,以C18柱进行反相分离;采用电喷雾电离源,以多反应监测（MRM）方式进行正离子检测。结果：血浆中关金刚测定线性范围为0．2-30μg·L^-1,最低定量限（LIDQ）为0．2μg·L^-1,r均大于0．99。日内和日间精密度均小于15％,绝对回收率大于79％。结论：该改良法选择性强、灵敏度高、重现性好,能快速、准确测定人血浆中关金刚浓度并成功应用于评估美金刚生物等效性的研究。     

Determination of hydrochlorothiazide in human plasma by liquid chromatography/tandem mass spectrometry

In this study, a fast and sensitive liquid chromatography/tandem mass spectrometry method for determination of hydrochlorothiazide in human plasma was developed and validated. The analyte and irbesartan, used as the internal standard, were precipitated and extracted from plasma using methanol. Analysis was performed on a Phenomenex Kromasil C₈ column with water and methanol (27:73, v/v) as the mobile phase. Linearity was assessed from 0.78 to 200 ng/mL in plasma. The analytical method proved to be applicable in a pharmacokinetic study after oral administration of 12 mg hydrochlorothiazide tablets to 20 healthy volunteers.     

液相色谱-串联质谱法测定人血浆中的龙胆苦苷浓度

目的:建立测定人血浆中龙胆苦苷浓度的液相色谱-串联质谱法。方法:血浆加入内标咖啡因后经固相萃取处理,采用 RESCEK C_8柱(150 mm×2.1 mm,5μm)分离,流动相为甲醇-10 mmol·L~(-1)醋酸铵溶液-乙腈(50:40:10),流速为0.2mL·min~(-1)。样品在三级四极杆串联质谱中经 ESI 源离子化后以多反应离子监测方式测定。结果:龙胆苦苷在3～5000 ng·mL~(-1)线性良好(r=0.9985),检测限为3 ng·mL~(-1),回收率为94.4%～104.2%,绝对回收率为92.4%～98.0%,日内、日间变异(RSD)均≤15%,色谱峰保留时间为2.25 min。结论:方法灵敏、准确、快速、特异性强,适用于中药龙胆苦苷的血药浓度测定和临床药代动力学研究。     

Simple and accurate quantitative analysis of ten antiepileptic drugs in human plasma by liquid chromatography/tandem mass spectrometry

A simple, accurate, and sensitive liquid chromatography (LC)-tandem mass spectrometry (MS/MS) method has been developed for the simultaneous quantification of 10 antiepileptic drugs (AEDs; gabapentin (GBP), levetiracetam (LEV), valproic acid (VPA), lamotrigine (LTG), carbamazepine-10,11-epoxide (CBZ-epoxide), zonisamide (ZNS), oxcarbazepine (OXC), topiramate (TPM), carbamazepine (CBZ), phenytoin (PHT)) in human plasma as a tool for drug monitoring. d₁₀-Phenytoin (d₁₀-PHT) and d_6-valproic acid (d₆-VPA) were used as internal standards for the positive- and negative-ionization modes, respectively. Plasma samples were precipitated by the addition of acetonitrile, and supernatants were analyzed on a C18 reverse-phase column using an isocratic elution. Detection was carried out in selected reaction monitoring (SRM) mode. The calibration curves were linear over a 50-fold concentration range, with correlation coefficients (r²) greater than 0.997 for all AEDs. The intra- and inter-day precision was less than 12%, and the accuracy was between 85.9 and 114.5%. This method was successfully used in the identification and quantitation of AEDs in patients undergoing mono- or polytherapy for epilepsy.     

LC-MS/MS法同时测定人血浆中氯吡格雷及其羧酸代谢物的浓度

目的建立快速测定人血浆中氯吡格雷及其羧酸代谢物SR26334含量的LC-MS/MS法。方法乙醚-正己烷(4:1,V:V)2次液-液提取法(中性和酸化条件下),采用Teknokroma C_(18)色谱柱,以那格列奈和吡格列酮为内标,同时测定血浆中氯吡格雷和SR26334的浓度。流动相:甲醇-0.1%甲酸(80:20,V:V);流速:0.2mL·min~(-1);以多反应离子监测方式检测:氯吡格雷[M+H]~+,m/z 322.1→212.1;那格列奈[M+H]~+,m/z 318.3→166.2;氯吡格雷羧酸代谢物SR26334[M+H]~+,m/z 308.1→q98.1;吡格列酮[M+H]~+,m/z 357.2→134.2。结果氯吡格雷和内标那格列奈的保留时间分别在4.4和3.7min,SR26334和内标吡格列酮的保留时间分别在1.3和1.7min,氯吡格雷的线性范围为5～5000ng·L~(-1);SR26334的线性范围为20～2500μg·L~(-1)。提取回收率大于75%,方法回收率大于90%,日内、日间RSD小于10%(n=5)。结论本方法简便快速,适用于氧吡格雷制剂的新药临床研究和临床长期治疗病人血药浓度的常规监测。     

LC-MS/MS法测定人血浆中替加色罗的浓度及其

目的:建立灵敏、快速的LC-MS/MS法测定人血浆中替加色罗,并用于制剂生物等效性研究。方法:血浆样品经有机溶剂提取后,以乙腈-5 mmol.L-1乙酸铵-甲酸(70∶30∶0.01)为流动相,采用Zorbax XDB-C18柱(150 mm×4.6 mm,5μm)分离,通过电喷雾离子化四极杆串联质谱,以多反应监测(MRM)方式进行检测。用于定量分析的离子反应分别为m/z302→173(替加色罗)和m/z256→167(内标苯海拉明)。结果:替加色罗测定方法的线性范围为0.010~10 ng.mL-1,定量下限为0.010 ng.mL-1,日内、日间精密度(RSD)均<7.3%,准确度(RE)在±1.4%之内。应用此法研究比较了22例健康受试者单剂量口服替加色罗参比制剂和受试制剂6 mg后的主要药动学参数,受试制剂和参比制剂Tmax分别为(0.86±0.22)和(1.01±0.24)h,Cmax分别为(2.21±0.69)和(2.05±0.64)ng.mL-1,t1/2α分别为(1.18±0.44)和(1.24±0.56)h,t1/2β分别为(10.10±3.07)和(8.81±2.35)h,AUC0~36 h分别为(6.35±2.48)和(6.47±1.99)ng.h.mL-1,AUC0~∞分别为(6.69±2.59)和(6.70±2.03)ng.h.mL-1。马来酸替加色罗分散片的相对生物利用度平均为(98.2±22.1)%。结论:该法灵敏、快速、准确,适用于替加色罗制剂的人体生物等效性评价。     

液-质联用测定人血浆中罗红霉素浓度

目的:建立高效液相色谱-质谱联用法测定人血浆中罗红霉素浓度。方法:以克拉霉素为内标,血浆样品经乙腈沉淀后,经HPLC-MS/MS分离分析。采用Waters ODS C18柱(2.1mm×50mm,3.5μm),以甲醇-5mmol.L-1醋酸铵(含0.03%甲酸)(55∶45)为流动相;流速:0.2mL.min-1,采用电喷雾离子源(ESI),以多离子反应监测方式(MRM)进行正离子监测,罗红霉素和内标克拉霉素的定量分析离子对分别为m/z837.5→679.4和m/z748.5→590.3。结果:罗红霉素血浆浓度测定方法线性范围为0.02025~13.500mg.L-1,r=0.999 0。定量下限为0.02025mg.L-1,方法回收率在85%~115%之间。日内和日间RSD均小于15%。结论:本试验所建立的方法灵敏、准确、可靠,适于罗红霉素的人体内药动学研究。     

Development and validation of a simple and sensitive liquid chromatography–tandem mass spectrometry method for quantifying trimetazidine in human plasma

1. A simple and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS‐MS) method for quantifying trimetazidine in human plasma was developed and validated. Sample preparation was based on deproteinating with acetonitrile. 2. Chromatography was performed on a C18 analytical column (5 μm; 150 × 2.1 mm i.d.) and the retention times for trimetazidine and cetirizine (used as the internal standard) were 1.8 and 3.0 min, respectively. The ionization was optimized using an electrospray ionization source and enhanced selectivity was achieved using tandem mass spectrometry. The calibration curve ranged from 0.1 to 200 ng/mL. The inter‐day precision, accuracy and the relative standard deviation (RSD) were all < 15%. The analyte was shown to be stable over the time‐scale of the entire procedure. 3. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.     

液相色谱-串联质谱法测定人血浆中雷洛昔芬及其在制剂生物等效性研究中的应用

目的:建立专属、灵敏的液相色谱-串联质谱法(LC-MS/MS)法测定人血浆中的雷洛昔芬,并将方法应用于雷洛昔芬两种制剂的人体生物等效性研究。方法:血浆样品中加入200μLβ-葡萄糖苷酸酶于37℃水浴孵化10 h后采用液-液萃取法预处理。Agilent Zorbax SB-C18色谱柱(150 mm×4.6 mm,5μm)进行分离,流动相为甲醇-醋酸铵(5 mmol.L-1)-甲酸(65∶35∶0.1),流速为0.6 mL.min-1。大气压化学电离源,多反应监测方式(MRM)进行正离子检测,定量分析离子对为m/z 474→m/z 112(雷洛昔芬)和m/z 478→m/z116(内标d4-雷洛昔芬)。临床试验采用随机双交叉设计,24例健康男性受试者空腹单次口服60 mg雷洛昔芬受试制剂或参比制剂,LC-MS/MS法测定血浆雷洛昔芬浓度,计算有关药代动力学参数并进行生物等效性评价。结果:雷洛昔芬定量方法线性范围为0.20～250 ng.mL-1,定量下限为0.20 ng.mL-1,日内、日间精密度(RSD)均小于11.2%,准确度(RE)在-4.0%～1.3%之间。两种制剂的AUC0～120无显著性差异,Cma...     

高效液相色谱-串联质谱法测定血浆中熊去氧胆酸的浓度

目的：建立高效液相色谱-质谱联用的方法测定人血浆内的熊去氧胆酸浓度的方法。方法：采用Shimadzu VP-ODS(4．6 mm×150 mm,5μm)色谱柱；柱温25℃；流动相为(A)乙腈-水(含5 mmol·L~(-1)的乙酸铵)(35：65,V/V),(B)乙情；梯度程序为0～2min,A：B=94：6；2～4．5min,A：B= 80：20：4．5～7min,A：B=94：6；流速为1．0 mL·min~(-1)；通过液相串联质谱,电喷雾离子源(ESI),以选择反应监测(SRM)方式进行检测；离子极性监测负离子(-)；检测离子为熊去氧胆酸m/z 391．1 [M-H]~-→391．1[M-H]~-,盐酸西替利嗪(内标)m/z 387．1[M-H]~-→387．1[M-H]~-。结果：熊去氧胆酸的最低定量限为40．144μg·L~(-1),线性范围为40．14～12 043μg·L~(-1)(r=0．995)。结论：该方法简便、灵敏度高,可以用来进行熊去氧胆酸的人体药动学和生物等效性研究。     

紫杉醇及其人血浆中代谢物的电喷雾串联质谱研究

目的:采用电喷雾串联质谱(ESI-MSn)法研究紫杉醇的离子化方式、结构裂解方式及在人血浆中的主要代谢物。方法:紫杉醇对照品溶液经质谱进样,探索其一级质谱的电离规律和二级质谱的裂解规律。通过液相色谱-质谱联用技术分离和鉴定紫杉醇在人体中的代谢物。结果:溶液中的添加剂对紫杉醇的离子化效率有明显促进作用,在ESI正离子模式下紫杉醇以m/z854的[M+H]+丰度最高。紫杉醇裂解过程以脱水和酯键断裂为主,产生多个碎片离子,其中m/z286信号最强并具有较好的稳定性。紫杉醇在人血浆中的代谢物有3个,以6α-羟基紫杉醇为主。结论:紫杉醇及其人血浆中代谢物的质谱行为研究,可为紫杉醇的质谱定性和定量分析以及药物代谢研究提供重要参考。     

Quantification of artemisinin in human plasma using liquid chromatography coupled to tandem mass spectrometry

A liquid chromatographic tandem mass spectroscopy method for the quantification of artemisinin in human heparinised plasma has been developed and validated. The method uses Oasis HLB™ μ-elution solid phase extraction 96-well plates to facilitate a high throughput of 192 samples a day. Artesunate (internal standard) in a plasma–water solution was added to plasma (50 μL) before solid phase extraction. Artemisinin and its internal standard artesunate were analysed by liquid chromatography and MS/MS detection on a Hypersil Gold C18 (100 mm × 2.1 mm, 5 μm) column using a mobile phase containing acetonitrile–ammonium acetate 10 mM pH 3.5 (50:50, v/v) at a flow rate of 0.5 mL/min. The method has been validated according to published FDA guidelines and showed excellent performance. The within-day, between-day and total precisions expressed as R.S.D., were lower than 8% at all tested quality control levels including the upper and lower limit of quantification. The limit of detection was 0.257 ng/mL for artemisinin and the calibration range was 1.03–762 ng/mL using 50 μL plasma. The method was free from matrix effects as demonstrated both graphically and quantitatively.     

高效液相色谱-串联质谱法测定血浆中黄豆苷元的浓度

目的:建立高效液相色谱-串联质谱联用(LC-MS-MS)的方法测定人血浆内黄豆苷元的浓度,并应用于药动学研究和生物等效性评价。方法:以木犀草素为内标,甲醇(含0．2%乙酸)为蛋白沉淀剂,采用Merck LiChroCART C_(18)色谱柱分离,通过LC-MS-MS电喷雾离子源(ESI),以选择反应监测(SRM)方式进行检测,离子极性监测为负离子,用于定量分析的离子分别为黄豆苷元m／z 252．9,木犀草素m／z 284．8。结果:血浆中的杂质不干扰黄豆苷元和木犀草素的测定,线性范围为0．1004～80．32μg·L~(-1)(r=0．994 0),血浆中黄豆苷元的绝对回收率大于80%,浓度为0．4016,4．016和40．16μg·L~(-1)的QC样品的批内和批间精密度RSD均小于10%。结论:该方法简便准确、灵敏度高,可以用于黄豆苷元的人体药动学研究和生物等效性评价。     

A sensitive liquid chromatography and mass spectrometry method for the determination of posaconazole in human plasma

Posaconazole is a novel extended-spectrum triazole that has favorable in vitro, in vivo and clinical activity against a number of yeasts and moulds. Posaconazole is available as an oral suspension. The dosage found to result in monitored plasma levels that correlate with clinical evidence of good antifungal activity is 800 mg/day in divided doses. A liquid chromatographic/mass spectrometric method (LC-MS/MS) that can be used by clinicians wishing to quantitate, and thereby monitor, plasma levels of posaconazole in certain patients was validated. The method utilized semi-automated 96-well protein precipitation with gradient chromatographic separation of analytes using a Varian Polaris C-18A (2.0 mm x 50 mm, 5-microm particle size) column. The approximate retention time of posaconazole was 2.0 min. Analytes were detected by using tandem mass spectrometry. Sample introduction and ionization was performed by atmospheric pressure chemical ionization in the positive-ion mode. This method has been proven suitable for routine quantitation of posaconazole over the concentration range of 5.00-5000 ng/mL. Inter-run precision based on percent relative deviation for replicate quality controls was < or = 6.2%. Inter-run accuracy expressed as %DIFF was +/-4.0%. Posaconazole quality controls were stable in human plasma for up to five freeze-thaw cycles, when frozen at -20 degrees C for at least 105 days and when kept at room temperature for 24 h. The lower limit of quantitation was 5.00 ng/mL for a 100-microL sample aliquot. These data indicate that the LC-MS/MS method described is suitable for the rapid measurement of posaconazole over the concentration range of 5.00-5000 ng/mL.     

Determination of fentanyl in human plasma by head-space solid-phase microextraction and gas chromatography-mass spectrometry

A head-space solid-phase microextraction (HS-SPME) method coupled to GC–MS was developed to extract fentanyl from human plasma. The protein binding was reduced by acidification and, eventually, the sample was deproteinized with trichloroacetic acid. The parameters influencing adsorption (extraction time, temperature, pH and salt addition) and desorption (desorption time and temperature) of the analyte on the fibre were investigated and validated for method development. The developed method proved to be rapid, simple, easy and inexpensive and offers high sensitivity and reproducibility. Linear range was obtained from 0.1 ng/ml to 2 μg/ml. The limit of detection was 0.03 ng/ml while an inter-day precision of less than 5% (n = 15) could be achieved. The method has been applied for the determination of fentanyl in plasma samples after application of 50 μg/h Duragesic fentanyl patch.     

High performance liquid chromatography-tandem mass spectrometric determination of rupatadine in human plasma and its pharmacokinetics

A simple, rapid, sensitive and selective liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the quantification of rupatadine in human plasma using estazolam as internal standard (IS). Following liquid-liquid extraction, the analytes were separated using a mobile phase of methanol-ammonium acetate (pH 2.2; 5mM) (50:50, v/v) on a reverse phase C18 column and analyzed by a triple-quadrupole mass spectrometer in the positive ion and multiple reaction monitoring (MRM) mode, m/z 416-->309 for rupatadine and m/z 295-->267 for the IS. The assay exhibited a linear dynamic range of 0.1-100 ng/ml for rupatadine in human plasma. The lower limit of quantification (LLOQ) was 0.1 ng/ml with a relative standard deviation of less than 20%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The validated LC-MS/MS method has been successfully applied to study the pharmacokinetics of rupatadine in healthy volunteers.     

Sensitive determination of nefopam and its metabolite desmethyl-nefopam in human biological fluids by HPLC

Nefopam (NEF) and desmethyl-nefopam (DMN) were assayed simultaneously in plasma, globule and urine samples using imipramine as internal standard. A liquid-liquid extraction procedure was coupled with a reverse phase high-performance liquid chromatography system. This system requires a mobile phase containing buffer (15 mM KH(2)PO(4) with 5 mM octane sulfonic acid: pH 3.7) and acetonitrile (77:33, v/v) through (flow rate=1.5 ml/min) a C(18) Symmetry column (150x4.6 I.D., 5 micrometer particle size: Waters) and a UV detector set at 210 nm. Internal standard was added to 1 ml of plasma or globule sample or 0.5 ml of urine sample, prior to the extraction under alkaline ambiance with n-hexane. The limits of quantification were 1 and 2 ng/ml for both molecules in plasma and globule, respectively; 5 and 10 ng/ml for NEF and DMN in urine, respectively. The method proved to be accurate and precise: the relative error at three concentrations ranged from -13.0 to +12.3% of the nominal concentration for all molecule and biological fluid; the within-day and between-day precision (relative standard deviation %) ranged from 1.0 to 10.1% for all the molecules and biological fluids. The method was linear between 1 and 60 ng/ml for both molecules in the plasma; 2 and 25 ng/ml for both molecules in the globule; 25 and 250 ng/ml for NEF and 50 and 500 ng/ml for DMN in the urine: correlation coefficients of calibration curves (determined by least-squares regression) of each molecule were higher than 0.992 whatever the biological fluid and during the pre-study and in-study validations. This method was successfully applied to a bio-availability study of NEF in healthy subjects.