Pharmacokinetic study of matrine, oxymatrine and oxysophocarpine in rat plasma after oral administration of Sophora flavescens Ait. extract by liquid chromatography tandem mass spectrometry

A rapid, sensitive and selective high-performance liquid chromatography tandem mass spectrometric method (HPLC-MS) has been developed and validated for the simultaneous determination of matrine (MT), oxymatrine (OMT) and oxysophocarpine (OSP) in rat plasma after oral administration of Sophora flavescens Ait. extract using pseudoephedrine hydrochloride as an internal standard (I.S.). The three analytes were extracted from the plasma samples by liquid-liquid extraction with chloroform. The chromatographic separation was accomplished on a Kromasil C18 column (150 mm x 4.6 mm). Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The total run time was 12 min between injections. The assay had a lower limit of quantification of 1.0 ng/ml for MT, 2.0 ng/ml for OMT and 2.0 ng/ml for OSP using 200 microl of plasma. The calibration curves were linear in the measured range. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. The proposed method enables unambiguous identification and quantification of MT, OMT and OSP in vivo. This was the first report on determination of the major quinolizidine alkaloids in rat plasma after oral administration of Sophora flavescens Ait. extract. The results provided a meaningful basis for evaluating the clinical applications of the herbal medicine.     

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.     

Rapid simultaneous quantification of five active constituents in rat plasma by high-performance liquid chromatography/tandem mass spectrometry after oral administration of Da-Cheng-Qi decoction

A rapid, sensitive and specific liquid chromatography-electrospray ionization/tandem mass spectrometry (LC-ESI/MS/MS) method has been developed and validated for simultaneous determination of five active constituents (including magnolol, honokiol, rhein, emodin and aloe-emodin) from Da-Cheng-Qi decoction (DCQD) in rat plasma. After the addition of gliquidone as the internal standard (IS), plasma samples were prepared by one-step protein precipitation using methanol and separated by HPLC on a short reversed phase C(18) column packed with smaller particles (100 mm x 3.0 mm, 3.5 microm) using a mobile phase of methanol-0.1% formic acid aqueous solution (70:30, v/v). Analytes were determined in a triple-quadrupole mass spectrometer in the selected reaction-monitoring (SRM) mode using electrospray source with negative mode. The method was proved to be rapid, sensitive, specific, accurate and reproducible and has been successfully applied to the determination of the five compounds in rat plasma after oral administration of low dose DCQD for pharmacokinetic study.     

Determination and pharmacokinetics of isoferulic acid in rat plasma by high-performance liquid chromatography after oral administration of isoferulic acid and Rhizoma Cimicifugae extract

A simple and specific high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) absorbance detection has been developed for the determination of isoferulic acid in rat plasma. The plasma samples were deproteinized with methanol after the addition of internal standard (IS) tinidazole. The analysis was performed on a Kromasil C18 column (250 mm x 4.6 mm i.d., 5 microm particle size) with acetonitrile-0.05% phosphoric acid (25:75, v/v) as mobile phase. The linear range was 0.0206-5.15 microg ml(-1) and the lower limit of quantification (LLOQ) was 0.0206 microg ml(-1). The intra- and inter-day relative standard deviations (R.S.D.s%) were less than 11.4 and 12.3%, respectively, and accuracy as relative error (R.E.%) between -6.7 and -1.1%. Mean extraction recovery was above 80%. The validated method was successfully applied to the pharmacokinetic study of isoferulic acid in rat plasma after oral administration of isoferulic acid and Rhizoma Cimicifugae extract.     

Determination of myrtucommulone from Myrtus communis in human and rat plasma by liquid chromatography/tandem mass spectrometry

Recent studies revealed that the non-prenylated acylphloroglucinol myrtucommulone (MC) from myrtle ( MYRTUS COMMUNIS) potently suppresses the biosynthesis of eicosanoids by direct inhibition of cyclooxygenase-1, microsomal prostaglandin E2 synthase (mPGES)-1, and 5-lipoxygenase at IC?? values in the range of 1 to 29 μM. Moreover, MC showed potent efficacy in animal models of inflammation after intraperitoneal administration. Since the main prerequisite for therapeutic efficacy is sufficient bioavailability, it is important to evaluate whether the concentrations of MC achieved in plasma coincide with the pharmacological active concentrations determined in vitro. For that reason, a sensitive LC/MS/MS method has been developed and validated for the determination of MC in human plasma. This method is based on liquid-liquid extraction of plasma samples with 20 % ethyl acetate in tert-butyl methyl ether using the structurally related acylphloroglucinol hyperforin as the internal standard. Chromatographic separation was achieved on a Gemini C6 Phenyl column using a mixture of acetonitrile/water (85 : 15 v/v) containing 6 mM ammonium formate in a run time of 15 min at a flow rate of 1 mL/min, a column temperature of 40 °C, and an autosampler temperature of 5 °C. Mass spectrometric quantification was carried out in the negative ion mode using electrospray ionization (ESI) and multiple-reaction monitoring (MRM). The most intense [M-H]? MRM transition at m/z 667.4 → m/z 194.9 was used for quantification of MC and the transition at m/z 535.4 to m/z 383.2 was used to monitor hyperforin. The method was linear in the range of 1-100 ng/mL with r > 0.998, an intra- and inter-day RSD of 1.1-8.4 and 7.1-11.8 %, respectively, and a maximum R. E. of 13.8 % at the lowest concentration level. Moreover, cross validation revealed the suitability of the developed LC/MS method for application in rat studies.     

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。     

Determination of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry

A sensitive and rapid method was developed for quantification of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry (LC–MS/MS). An aliquot of 1 mL plasma sample was extracted with ethyl acetate–dichloromethane. Separation of olprinone and the milrinone (internal standard, IS) from the interferences was achieved on a C₁₈ column followed by MS/MS detection. The analytes were monitored in the positive ionization mode. Multiple reaction monitoring using the transition of m/z 251 → m/z 155 and m/z 212 → m/z 140 was performed to quantify olprinone and IS, respectively. The method had a total chromatographic run time of 3 min and linear calibration curves over the concentration range of 0.5–60 ng/mL. The lower limit of quantification (LLOQ) was 0.5 ng/mL. The intra- and inter-day precisions were less than 16.3% for low QC level, and 7.1% for other QC levels, respectively. The intra- and inter-day relative errors were ranged between −12.2% and 3.7% for three QC concentration levels. The validated method was successfully applied to the quantification of olprinone concentration in human plasma after intravenous (i.v.) administration of olprinone at a constant rate of infusion of 2 μg/(kg min) for 5 min in order to evaluate the pharmacokinetics.     

Determination of imperatorin in rat plasma by reversed-phase high-performance liquid chromatography after oral administration of Radix Angelicae dahuricae extract

A simple high-performance liquid chromatographic (HPLC) method has been developed for the determination of imperatorin in rat plasma and applied to a pharmacokinetic study in rats after administration of Radix Angelicae dahuricae extract. After addition of fluocinonide as an internal standard (IS), plasma samples were extracted with diethyl ether. HPLC analysis of the extracts was performed on a Diamonsil C18 analytical column using methanol–water (70:30, v/v) as the mobile phase. The UV detector was set at 254 nm. The standard curve was linear over the range 0.04–4.0 μg/mL. The lower limit of quantification was 0.04 μg/mL. The HPLC method developed could be easily applied to the determination and pharmacokinetic study of imperatorin in rat plasma after giving the animals Radix Angelicae dahuricae extract.     

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。     

Determination of febuxostat in human plasma using ultra‐performance liquid chromatography tandem mass spectrometry

A rapid and sensitive liquid chromatography‐tandem mass spectrometry method has been developed and validated for the determination of febuxostat in human plasma. The liquid‐liquid extraction technique was used for the extraction of febuxostat from human plasma using trandolapril as the internal standard (IS). Chromatography was performed on a ultra‐performance liquid chromatography (UPLC) BEH C18, 50 mm X 2.1 mm, 1.7 µm particle size column, with the mobile phase consisting of 0.1% formic acid and acetonitrile (in a 25:75 ratio), followed by detection using mass spectrometry. The method involves a simple reversed isocratic chromatography condition and mass spectrometry detection, which enables detection at sub‐microgram levels. The method was validated and the lower limit of quantification for febuxostat was found to be 0.075 µg/ml. The mean recovery for febuxostat ranged from 100.9 to 106.5%. This method increased the sensitivity and selectivity; resulting in high‐throughput analysis of febuxostat using commercially available IS for pharmacokinetic, bioavailability, and bioequivalence studies, with a chromatographic run time of 1.5 min only. Copyright © 2012 John Wiley & Sons, Ltd.     

Determination of strychnine and brucine in rat plasma using liquid chromatography electrospray ionization mass spectrometry

A simple, sensitive and selective liquid chromatography–electrospray mass spectrometric (LC–ESI-MS) method was developed and validated for simultaneous determination of strychnine and brucine in rat plasma, using tacrine as the internal standard (IS). Sample preparation involved a liquid–liquid extraction of the analytes with n-hexane, dichloromethane and isopropanol (65:30:5, v/v/v) from 0.1 mL of plasma. Chromatographic separation was carried out on a Waters C₁₈ column using a mobile phase of methanol–20 mM ammonium formate–formic acid (32:68:0.68, v/v/v). Positive selected ion monitoring mode was used for detection of strychnine, brucine and the IS at m/z 335.2, m/z 395.2 and m/z 199.2, respectively. Linearity was obtained over the concentration range of 0.5–500 ng/mL for strychnine and 0.1–100 ng/mL for brucine. The lower limit of quantification was 0.5 ng/mL and 0.1 ng/mL for strychnine and brucine, respectively. The intra- and inter-day precision for both strychnine and brucine was less than 7.74%, and accuracy ranged from −4.38% to 2.21% at all QC levels. The method has been successfully applied to a pharmacokinetic study of processed Semen Strychni after oral administration to rats.     

Determination of free levels of phenytoin in human plasma by liquid chromatography/tandem mass spectrometry

A liquid chromatography combined with tandem mass spectrometry assay for the determination of free levels of the highly protein bound drug phenytoin (5,5-diphenylhydantoin) in human plasma is described. The assay was demonstrated to be reliable, accurate and precise, and specific for phenytoin. The procedure involves isolation of the unbound drug from the drug/protein complex by ultrafiltration. Liquid-liquid extraction was employed to extract the resultant ultrafiltrate. PHT was separated on a 50 x 3 mm reversed-phase column using isocratic mobile phase conditions that yielded a run time of 1.5 min, enabling high throughput sample analysis. Linearity was obtained over the range 5.00 to 500 ng/ml. Both between-run and within-run coefficients of variation were less than 15% and accuracy's across the assay range were all within 100 +/- 10%. The assay was successfully implemented to support a clinical interaction study with phenytoin.     

Analysis of CoQ10 in rat serum by ultra-performance liquid chromatography mass spectrometry after oral administration

A UPLC-MS method for determining Coenzyme Q(10) (CoQ(10)) levels in rat serum was developed. CoQ(10) was quantitatively extracted into 2-propanol using a fast extraction procedure. The separation of CoQ(10) was performed on a Waters Acquity UPLCtrade mark BEH C(18) column (1.7 microm, 1.0 mm x 50 mm) with the mobile phase containing acetonitrile, 2-propanol, and formic acid (90:10:0.1) over 5 min. The sensitivity of this method allows for the quantitation of 50 ng/mL CoQ(10) in serum (S/N=10). The linearity of this method was found to be from 50 to 20,000 ng/mL. The precision was less than 10% (intra- and inter-day), and the average extraction recovery was between 90 and 105%. This procedure provides a precise, sensitive and direct assay method for the determination of CoQ(10) in rat serum after oral administration. This method could be applied to further pharmacokinetic studies of CoQ(10).     

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...     

Metabolite profile analysis of aconitine in rabbit stomach after oral administration by liquid chromatography/electrospray ionization/multiple-stage tandem mass spectrometry

Abstract

1. Aconitine (AC), an active and highly toxic constituent extracted from aconitum plants, is well known for its excellent effects against rheumatism and rheumatoid arthritis. The metabolism of AC in liver and intestine has been previously reported. However, little is known about the metabolism of AC in stomach. In this study, the metabolite profiling of AC in stomachs of rabbit and rat was performed by liquid chromatography/electrospray ionization/multiple-stage tandem mass spectrometry (LC/ESI/MSⁿ), for the first time.

2. The samples were purified by liquid–liquid extraction, separated using an Agilent extended C18 column following a linear gradient elution and then detected by ESI/MSⁿ in positive ion mode. Metabolites were identified by comparing their protonated molecules, fragmentation patterns and chromatographic behaviors with those of standard compounds and data from authorized literature works.

3. In conclusion, 14 metabolites were identified in animal stomach after oral administration of AC. The presentation of a large amount of metabolites of AC in stomach suggested that, for aconitum alkaloids, the stomach might play an important role in their metabolism.     

高效液相色谱-质谱/质谱联用法测定人血浆中莫沙必利

建立测定人血浆中莫沙必利的高效液相色谱-质谱/质谱联用法。取血浆样品经液-液萃取后，以乙腈为有机相，0.3%甲酸水溶液为水相，采用梯度洗脱的方式，用C₁₈柱分离，通过电喷雾离子化，以多反应监测(MRM)方式进行正离子检测。莫沙必利线性范围为0.17~68.00 ng·mL^-1，定量下限为0.17 ng·mL^-1，每个样品测试时间仅2.8 min，日内、日间精密度(RSD)均小于13%，准确度(RE)在±6.3%范围内。应用此法研究了20名志愿者单剂量口服枸橼酸莫沙必利片后的药代动力学特点。该方法、灵敏、准确、快速，适用于莫沙必利的药代动力学及生物等效性研究。     

Determination of moxifloxacin in human plasma by liquid chromatography electrospray ionization tandem mass spectrometry

Moxifloxacin is an advanced-generation, 8-methoxy fluoroquinolone that is active against a broad spectrum of pathogens, including antibiotic resistant Streptococcus pneumoniae. Development of a rapid, sensitive and selective method for the determination of moxifloxacin in human plasma is essential for understanding the pharmacokinetics of the drug when administered orally or intravenously. Solid phase extraction (SPE) using Oasis(R) HLB was used to extract moxifloxacin and the internal standard lomefloxacin from plasma. A method based on liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) was developed and validated to quantitate moxifloxacin in human plasma. The precursor and major product ion of the analyte was monitored on a triple quadrupole mass spectrometer with positive ion electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. Mechanisms for the formation of collision-induced dissociation (CID) products of moxifloxacin are proposed. Linear calibration curves were generated from 1 to 1000 ng/ml with coefficients of determination greater than 0.999. The inter-day and intra-day precision (% CV) was less than 11.3% and accuracy (% error) was less than 10.0% for moxifloxacin. The limit of detection (LOD) for the method was 50 pg/ml based on a signal to noise ratio of 3.     

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。     

Profiling impurities and degradants of butorphanol tartrate using liquid chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry substructural techniques

A rapid and systemic strategy based on liquid chromatography/mass spectrometry (LC/MS) profiling and liquid chromatography/tandem mass spectrometry (LC/MS/MS) substructural techniques was utilized to elucidate the degradation products of butorphanol, the active ingredient in stadol® NS. This strategy integrates, in a single instrumental approach, analytical HPLC, UV detection, full-scan electrospray mass spectrometry, and tandem mass spectrometry to rapidly and accurately elucidate structues of impurities and degradants. In these studies, several low-level degradation products were observed in long-term storage stability samples of bulk butorphanol. The resulting analytical profile includes information on five degradants including molecular structures, chromatographic behavior, molecular weight, UV data, and MS/MS substructural information. The degradation products formed during long-term storage of butorphanol tartrate included oxidative products proposed as 9-hydroxy- and 9-keto-butorphanol, norbutorphanol, a ring-contraction degradant, and Δ1, 10-butorphanol. These methodologies are applicable at any stage of the drug product cycle from discovery through to development. This library of butorphanol degradants provides a foundation for future development work regarding product monitoring, as well as a useful diagnosite tool for new degradation products.     

Determination of domperidone in human plasma using liquid chromatography coupled to tandem mass spectrometry and its pharmacokinetic study

A sensitive and selective liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of domperidone (CAS number: 57808-66-9) in human plasma using paracetamol (CAS number: 103-90-2) as an internal standard (IS). Domperidone and paracetamol in plasma were extracted with ethyl acetate, separated on a C18 reversed phase column, eluted with mobile phase of acetonitrile-glacial acetic acid (0.3%) (40:60, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor→product ions of m/z 426.2→175.1 for domperidone and 152→110 for the IS, respectively. The calibration curve was linear (r2≥0.99, n=5) over the concentration range of 0.2-80 ng/mL and with lower limit of detection and quantitation of 0.05 and 0.2 ng/mL. The speci?city, matrix effect, recovery, sensitivity, linearity, accuracy, precision, and stabilities were validated for domperidone in human plasma. In conclusion, the validation results showed that this method was sensitive, economical and less toxic and it can successfully ful?ll the requirement of clinical pharmacokinetic study of domperidone oral preparation in Chinese healthy volunteers.