高效液相色谱法测定大鼠血浆中的原儿茶酸

建立了大鼠血浆中原儿茶酸含量测定的高效液相色谱方法。采用的色谱柱为DiamondsilTM C18 柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水(体积比为9∶91,用H3PO4 调pH至2.5);流速1.2 mL/min;检测波长260 nm;内标为对羟基苯甲酸。原儿茶酸的线性范围为0.050~3.20 mg/L,线性相关系数为0.9978，最低定量限为0.050 mg/L,日内和日间测定的精密度（以相对标准偏差表示）均低于7.0%,准确度（以相对误差表示）为-1.4%～2.6%；在0.050,0.40,3.20 mg/L低、中、高3个添加浓度水平下，血浆样品的提取回收率分别为83.4%,87.3%,91.1%。该方法简便,灵敏,准确,适用于大鼠体内原儿茶酸的药物动力学研究。     

Determination of Geniposide in Rats Plasma. Application to Pharmacokinetic Studies of Sendeng-4 Decoction

A sensitive and simple high-performance liquid chromatographic (HPLC) method has been developed for determination of geniposide in rat plasma. The plasma was extracted with acetonitrile. Separation of the main effective constituent, geniposide, was accomplished on a reversed-phase ODS C₁₈ column (250 mm × 4.6 mm i.d., 5 µm particles) with acetonitrile-water, 12:88 (v/v), as mobile phase and UV detection at 238 nm. Paeoniflorin was used as the internal standard (IS). The calibration plot was linear over the range 0.0848–7.42 µg mL^?1. The lower limit of quantification was 0.0848 µg mL^?1. Intra-day precision was better than 11.4% and inter-day precision was better than 9.3%. Mean extraction recovery was 87.1%. The validated method was successfully used in pharmacokinetic studies of geniposide in rat plasma after oral administration of Sendeng-4 decoction. The pharmacokinetic study indicated that absorption of geniposide from Sendeng-4 decoction was rapid, as also was its subsequent elimination.     

高效液相色谱-质谱法测定比格犬血浆中的艾普拉唑及其药代动力学

运用高效液相色谱-电喷雾质谱(HPLC-ESI-MS)技术,建立了快速、简单、灵敏的比格犬静脉滴注艾普拉唑钠盐后血药浓度的检测方法。血浆样品采用蛋白沉淀法,以丁螺环酮作为内标,色谱柱为Teknokroma Kromasil C18(100 mm×2.1 mm, 5 μm),流动相为水-甲醇-乙腈(69:8:23, v/v/v)(含0.1%的甲酸),流速0.2 mL/min,采用电喷雾(ESI)离子源以正离子方式检测。绘制血药浓度-时间曲线,并采用DAS 2.0计算药代动力学参数。方法学实验结果表明内源性杂质不干扰艾普拉唑和内标的测定,线性范围为5～10000 μg/L (r=0.994),最低定量限为5 μg/L,精密度和准确度均符合生物样品测定的要求。低、中、高3个浓度的绝对回收率在106%左右,基质效应小于142.0%,表明该方法适合比格犬血浆中艾普拉唑浓度的测定及药代动力学研究。比格犬静脉滴注艾普拉唑钠盐3个剂量(0.2 mg/kg、0.8 mg/kg和3.2 mg/kg)后的药-时曲线下面积(AUC(0~∞))分别为(2.4×104±3×103)、(8.8×104±1.6×104)和(5.4×105±8×104) μg/L•min,呈线性药物代谢动力学过程。     

Simultaneous determination of etoposide and its catechol metabolite in the plasma of pediatric patients by liquid chromatography/tandem mass spectrometry

The anticancer drug etoposide is associated with leukemias with MLL gene translocations and other translocations as a treatment complication. The genotype of cytochrome P450 3A4 (CYP3A4), which converts etoposide to its catechol metabolite, influences the risk. In order to perform pharmacokinetic studies aimed at further elucidation of the translocation mechanism, we have developed and validated a liquid chromatography/electrospray/tandem mass spectrometry assay for the simultaneous analysis of etoposide and its catechol metabolite in human plasma. The etoposide analog teniposide was used as the internal standard. Liquid chromatography was performed on a YMC ODS-AQ column. Simultaneous determination of etoposide and its catechol metabolite was achieved using a small volume of plasma, so that the method is suitable for pediatric patients. The limits of detection were 200 ng ml(-1) etoposide and 10 ng ml(-1) catechol metabolite in human plasma and 25 ng ml(-1) etoposide and 2.5 ng ml(-1) catechol metabolite in protein-free plasma, respectively. Acceptable precision and accuracy were obtained for concentrations in the calibration curve ranges 0.2--100 microg ml(-1) etoposide and 10--5000 ng ml(-1) catechol metabolite in human plasma. Acceptable precision and accuracy for protein-free human plasma in the range 25--15 000 ng ml(-1) etoposide and 2.5--1500 ng ml(-1) etoposide catechol were also achieved. This method was selective and sensitive enough for the simultaneous quantitation of etoposide and its catechol as a total and protein-free fraction in small plasma volumes from pediatric cancer patients receiving etoposide chemotherapy. A pharmacokinetic model has been developed for future studies in large populations.     

HPLC determination of ferulic acid in rat plasma after oral administration of Rhizoma Chuanxiong and its compound preparation

An HPLC method is described for determination of ferulic acid in rat plasma. The concentration of ferulic acid in rat plasma was determined after deproteinization with acetonitrile using sulfamethoxazole as internal standard. Chromatographic separations were performed on a C(18) stationary phase with a mobile phase composed of acetonitrile-water (16:84, v/v) with 1% glacial acetic acid. The UV detection wavelength was set at 320 nm. The method was successfully applied to the determination of pharmacokinetic parameters in rat plasma after oral administration of Rhizoma Chuanxiong and and its compound preparation Suanzaoren decoctions. The calibration curve was linear over the range 0.0510-4.08 micro g/mL in rat plasma. Within-day and between-day precisions were less than 4.5% RSD. Mean recovery was determined as 96.9%. The limit of quantitation was 0.0510 micro g/mL. The pharmacokinetic parameters of the two preparations were different significantly (p < 0.05), which may attribute to the effects of other ingredients present in Suanzaoren decoction.     

High-Performance Liquid Chromatographic Determination of SAZ-VII-23, A Novel Antiarrhythmic Agent,in Dog Plasma and Urine

Abstract

A HPLC method has been developed to determine the concentrations of SAZ-VII-23 (3-benzoyl-7-isopropyl-3,7-diazabicyclo[3.3.1]nonane HClO₄), a novel antiarrhythmic agent, in dog plasma and urine. Plasma treated with acetonitrile and alkalinized urine were extracted with chloroform- propanol (9:1). An aliquot was injected on to HPLC system using a C₆ reversed-phase column and acetonitrile-methanol-37.5 mM phosphate buffer, pH 6.8 (28.5:28.5:43 v/v) containing 4.0 mM triethylamine as mobile phase. Detection wavelength was 255 nm. The linear range were 0.04–8 μg/ml, and the lower limit of quantitation was 0.04 μg/ml in plasma and urine, respectively. The method was applied to determine plasma and urine concentrations and preliminary pharmacokinetic profiles of SAZ-VII-23 in a dog.     

HPLC analysis and pharmacokinetics of icariin in rats

As a prerequisite to the determination of pharmacokinetic parameters of icariin in rats, an HPLC method using UV detection was developed and validated. Icariin and the internal standard, quercetin, were extracted from plasma samples using ethyl acetate after acidification with 0.05 mol/L NaH2PO4 solution (pH 5.0). Chromatographic separation was achieved on an Agilent XDB Cls column (250 x 4.6 mm id, 5 microm) equipped with a Shim-pack GVP-ODS C18 guard column (10 x 4.6 mm id, 5 microm) using a mobile phase of ACN/water/acetic acid (31:69:0.4 v/v/v) at a flow rate of 1.0 mL/ min. Detection was at 277 nm. The calibration curve was linear from 0.05 to 100.0 microg/mL with 0.05 microg/mL as the lower LOQ (LLOQ) in plasma. The intra- and interday precisions in terms of RSD were lower than 5.7 and 7.8% in rat plasma, respectively. The accuracy in terms of relative error (RE) ranged from -1.6 to 3.2%. The extraction recoveries of icariin and quercetin were 87.6 and 80.1%, respectively. The main pharmacokinetic parameters for rats were determined after a single intravenous administration of 10 mg/kg icariin: t1/2, 0.562 +/- 0.200 h; AUC0-infinity, 8.73 +/- 2.23 microg x h/mL; CLToT, 20.10 +/- 5.80 L/kg x h; Vz, 1.037 +/- 0.631 L/kg; MRT0-infinity, 0.134 +/- 0.040 h; and Vss, 0.170 +/- 0.097 L/kg.     

A highly sensitive liquid chromatography tandem mass spectrometry method for simultaneous quantification of midazolam, 1'-hydroxymidazolam and 4-hydroxymidazolam in human plasma

A highly sensitive liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of midazolam and its major metabolites 1'-hydroxymidazolam and 4-hydroxymidazolam in human plasma was developed and validated. Stable isotope-labeled midazolam-D(4) and 1'-hydroxymidazolam-D(4) were used as internal standards. Compounds were extracted from 0.5 mL plasma by liquid-liquid extraction with ethyl acetate-heptane (1:4). Chromatography was achieved using a Sunfire C(18) column. The mobile phase was a gradient with 10 m m formic acid in Milli-Q water and methanol at a flow rate of 0.3 mL/min. Total run time was 10 min. Detection was performed using a tandem mass spectrometer with positive electrospray ionization. Calibration curves were linear over the range of 0.10-50.0 ng/mL for midazolam and 0.025-25.0 ng/mL for both metabolites. For all compounds the lower limit of quantification was 0.10 ng/mL. Imprecision was assessed according to the NCCLS EP5-T guideline and was below 10% for all compounds. Mean recoveries were between 94 and 109% for midazolam and its metabolites. The validated method was successfully applied in a pharmacokinetic study investigating in vivo CYP3A-activity in a large cohort of renal allograft recipients using sub-therapeutic doses of midazolam as a drug-probe.     

UHPLC–MS/MS determination and pharmacokinetic study of plantamajoside in rat plasma after oral administration of single plantamajoside and Plantago asiatica extract

A sensitive and reliable ultra‐high performance liquid chromatography coupled with tandem quadrupole mass spectrometry (UHPLC–MS/MS) method was developed for quantitation of plantamajoside in rat plasma. First, this study compared the pharmacokinetic properties of plantamajoside after oral administration of Plantago asiatica extract and pure plantamajoside in rat plasma with approximately the same dosage of 8.98 mg/kg. Second, chromatographic separation was performed on an Acquity HSS C₁₈ column (50 × 2.1 mm, p.d.1.7 μm) with isocratic elution using methanol–water (80:20, v /v) as mobile phase at a flow rate of 0.25 mL/min. The calibration curves were linear over the range of 0.1–100 ng/mL for plantamajoside. At different time points (0, 0.083, 0.167, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6 and 8 h) after administration, the concentrations of plantamajoside in plasma were measured and the main pharmacokinetic parameters were estimated. The study indicates that the pharmacokinetics of plantamajoside in rat plasma have significant differences between two groups.     

Rapid determination of ranitidine in human plasma by high-performance liquid chromatography

Summary An HPLC method has been developed for the quantification of rantidine in plasma for pharmacokinetic studies. Metoclopramide was used as internal standard. The method uses a simple and rapid sample clean-up procedure involving single-step extraction with organic solvent to extract ranitidine from plasma. After evaporation and reconstitution the samples are chromatographed on a 250 mm×4 mm base-stable reversed-phase column with 0.05 M ammonium acetate-acetonitrile, 75∶25 (v/v) as mobile phase and UV detection at 313 nm. The calibration graph was linear for quantities of ranitidine between 10 and 2000 ng mL⁻¹. Intra- and inter-dayCV did not exceed 11.64%. The quantitation limit was 10 ng mL⁻¹ for human plasma. The applicability of this method for pharmacokinetic studies of ranitidine after oral administration are described. Approximately 90 samples can be processed in 24 h.     

Determination of exifone in human plasma and urine by high-performance liquid chromatography with electrochemical detection

A high-performance liquid chromatographic method with electrochemical detection was developed for the determination of exifone in human plasma and urine. Exifone was extracted from acidified plasma or neutralized urine with diethyl ether and the evaporated extracts were analysed on a C18 reversed-phase column. The compound was eluted in about 8 min with acetonitrile-0.3 M orthophosphoric acid (15:85, v/v) at a flow-rate of 0.9 ml/min. This method gave accurate and reproducible results; the calibration graphs were linear (r greater than 0.99) over the range of 2.8-360 nmol/l for plasma and 0.18-36 mumol/l for urine, and concentrations as low as 1 nmol/l in plasma could be quantified. These results allowed this assay to be used for determinations in single-dose pharmacokinetic studies.     

Solid phase extraction of oxcarbazepine and its metabolites from plasma for analysis by high performance liquid chromatography.

A rapid, sensitive and simple-to-operate high performance liquid chromatographic method for the simulataneous determination of oxcarbazepine, 10-hydroxycarbazepine and 10,11-dihydro-10,11-trans-dihydroxy-carbamazepine in plasma is described. The drug and its metabolites were extracted from plasma using commercially available reversed phase octadecylsilane bonded-silica columns (Bond Elut C18, 1 mL capacity). Chromatographic separation of oxcarbazepine and its metabolites was achieved using a mobile phase consisting of acetonitrile/methanol/water (13:25:62 by volume) at a flow rate of 1.2 mL/min in conjunction with a Waters Associates Nova-Pak C18 column. The analytical column, in Radial-Pak cartridge form, was used in combination with a LiChrospher 5 microns C18 guard column. By measuring the UV absorbance at 214 nm, plasma levels in the region of 50-100 ng/mL for the drug and its metabolites can be detected with only 100 microL of plasma. The method has been applied to pharmacokinetic studies of oxcarbazepine and its metabolites in children with epilepsy; preliminary pharmacokinetic findings in two patients at steady-state are presented.     

LC determination and pharmacokinetic study of vitexin-4″-O-glucoside in rat plasma after oral administration

A simple and specific high-performance liquid chromatography (HPLC) method was developed for the pharmacokinetic study of vitexin-4″-O-glucoside (VOG) in rats after oral administration. The plasma samples were deproteinised with methanol after the addition of an internal standard, hesperidin. HPLC analysis was performed on a Diamonsil C(18) analytical column, using methanol -0.5% aqueous phosphoric acid (45:55, v/v) as the mobile phase with ultraviolet detection at 330?nm. The calibration curve was linear over the range of 5-450?μg?mL(-1) in rat plasma. The average extraction recovery of VOG was 98.74%?±?0.44%, and the relative standard deviations of the intra- and inter-day precisions were not greater than 4.1% and 2.0%, respectively. The validated method was successfully applied during a pharmacokinetic study in rats after oral administration of VOG at different doses, and all the results indicated that the pharmacokinetics of VOG in rats obeyed nonlinear processes.     

Gas chromatographic method for determination of a piperazine derivative (Trelibet) and its metabolites in human plasma and urine

A sensitive gas chromatographic method was developed for the determination of Trelibet, 1-benzyl-4-(2'-pyridinecarbonyl)piperazine, and of its major metabolites in biological fluids. The compounds were extracted as bases into dichloromethane, and the extracts were analysed by a dimethylsilicone capillary column with a nitrogen-phosphorus flame-ionization detector. The lower limit of detection was 1 ng/ml for Trelibet and 5 ng/ml for the metabolites. Peak-area ratios of the compounds and internal standard were linearly correlated to their plasma concentrations between 1 and 1000 ng/ml. The method was used for quantification of Trelibet and two of its metabolites in depressed patients after oral administration of a single dose of 200 mg of Trelibet. Concentration data measured in plasma and urine showed that the method is sensitive enough to monitor concentrations both for pharmacokinetic studies and for plasma steady-state levels daily.     

Determination of a novel phosphodiesterase4 inhibitor, 3‐[1‐(3cyclopropylmethoxy‐4‐difluoromethoxybenzyl)‐1H‐pyrazol‐3‐yl]‐benzoic acid (PDE‐423) in rat plasma using liquid chromatography–tandem mass spectrometry

A method for determining a novel phosphodiesterase‐4 inhibitor, 3‐[1‐(3cyclopropylmethoxy‐4‐difluoromethoxybenzyl)‐1H‐pyrazol‐3‐yl]‐benzoic acid (PDE‐423), in rat plasma was developed and validated using liquid chromatography–tandem mass spectrometry for further pharmacokinetic study for development as a novel anti‐asthmatic drug. PDE‐423 in the concentration range of 0.02–10 µg/mL was linear with a correlation coefficient of >0.99, and the mean intra‐ and inter‐assay precisions of the assay were 7.50 and 3.86%, respectively. The validated method was used successfully for a pharmacokinetic study of PDE‐423 in rats. Copyright © 2014 John Wiley & Sons, Ltd.     

A simple and sensitive HPLC method for quantitation of low phenoprolamine hydrochloride concentrations in human plasma and its pharmacokinetic application

Phenoprolamine hydrochloride is a novel compound that works against a variety of types of hypertension. The purpose of this study was to develop a simple and sensitive high-performance liquid chromatographic method for quantitation of low phenoprolamine hydrochloride concentrations in human plasma and to apply it to pharmacokinetic study. The procedure involved extraction of the drug and clonidine (internal standard) from the plasma using diethyl ether. Chromatographic separations were carried out on a 4.6 x 200 mm Hypersil silica column with UV detection at 230 nm. The isocratic mobile phase, 1% ammonium acetate (pH 5.4) and methanol (0.3:99.7, v/v), was run at 1 mL/min. Extraction recovery was 84% for phenoprolamine hydrochloride at a concentration level of 200 ng/mL, and 76% for clonidine at 200 ng/mL. The method was linear in the concentration range 5-4000 ng/mL with a lower limit of quantitation of 5 ng/mL for phenoprolamine hydrochloride. Inter- and intra-day coefficients of variation were less than 10%. The validated method was successfully applied to a pharmacokinetic study in human after an oral administration of the drug, and the pharmacokinetic parameters are presented.     

The effectiveness of borneol on pharmacokinetics changes of four ginsenosides in Shexiang Baoxin Pill in vivo

Shexiang Baoxin Pill (SBP) is a traditional Chinese medicine, widely used for cardiovascular diseases in the clinic. Ginsenosides are important effective components in SBP, but their pharmacokinetic characteristics are still not known. In this paper, we studied the pharmacokinetics of ginsenoside Rb1, Rc, Re and Rg1 in SBP and investigated the effect of borneol on the pharmacokinetic characteristic of ginsenosides based on an Agilent G6410A triple quadrupole LC/MS system. Results showed that the pharmacokinetic parameters of ginsenoside Rb1, Rc, Re and Rg1 in rat plasma after oral administration of SBP are significantly different with oral administration of SBP without Borneolum Syntheticum. Plasma pharmacokinetic profiles after oral administration of ginsenoside Rb1, Rc, Re, Rg1 and co‐administration with borneol at three different ratios (10:1, 1:1 and 1:10 ginsenoside vs borneol, w/w) were also determined. It was demonstrated that borneol can elevate the plasma concentration of ginsenosides after co‐admininstration. Copyright © 2013 John Wiley & Sons, Ltd.     

Stereoselective determination of the enantiomers of methadone in plasma using high-performance liquid chromatography.

An enantioselective high-performance liquid chromatographic assay for the quantification of methadone in human and beagle plasma is described. The procedure involves extraction of methadone from alkalized plasma into hexane-isoamyl alcohol (99:1, v/v). Stereoselective separation was achieved with a silica column with covalently bound alpha 1-acid glycoprotein (Chiral-AGP) without any derivatization procedure. The detection wavelength was set at 215 nm. Using an internal standard provided reliable control of the extraction procedure as well as quantification of the enantiomers of methadone. The limit of quantification was found to be 2.5 ng/ml. The method was demonstrated to be sufficiently sensitive for stereoselective pharmacokinetic studies of methadone.     

Simultaneous determination of paclitaxel and a new P-glycoprotein inhibitor HM-30181 in rat plasma by liquid chromatography with tandem mass spectrometry

An LC-MS/MS method for the simultaneous determination of a new P-glycoprotein inhibitor 4-oxo-4H-chromene-2-carboxylic acid [2-(2-(4-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-ethyl]-phenyl)-2H-tetrazol-5-yl)-4,5-dimethoxy-phenyl]-amide (HM-30181) and a P-glycoprotein substrate paclitaxel in rat plasma was developed to simultaneously evaluate the pharmacokinetics of paclitaxel and HM-30181 in the rats. HM-30181, paclitaxel, HM-30059 (internal standard (I.S.) for HM-30181), and docetaxel (I.S. for paclitaxel) were extracted from rat plasma with methyl-tert-butyl ether and analyzed on an Atlantis C18 column (5 microm, 2.1 x 100 mm) with the mobile phase of ACN/10 mM ammonium formate (75:25 v/v). The analytes were detected using an ESI MS/MS in the multiple reaction monitoring (MRM) mode. The standard curves for HM-30181 and paclitaxel in plasma were linear (r > 0.999) over the concentration range of 2.0-500 ng/mL with a weighting of 1/concentration2. The method showed a satisfactory sensitivity (2 ng/mL using 50 microL plasma), precision (CV: < or = 6.6%), accuracy (relative error: -6.3 to 2.0%), and selectivity. This method was successfully applied to the pharmacokinetic study of HM-30181 and paclitaxel in rat plasma after oral-coadministration of paclitaxel and HM-30181 to male Sprague- Dawley rats.     

High-performance liquid-chromatographic determination of rifampicin in plasma and tissues

A HPLC-UV method has been developed for assaying rifampicin in plasma and liver. The assay involved a liquid-liquid extraction procedure with dichloromethane-pentane (1:1). An Ultrabase-C18 column and a simple mobile phase consisting of a water (pH 2.27)-acetonitrile (40:60, v/v) mixture were used. The flow-rate was 1 ml/min and the effluent was monitored at 333 nm. Results from the HPLC analyses showed that the assay method is linear in the ranges 0.1-1 and 1-50 microg/ml for plasma, and 0.6-40 microg/g for liver. Intra- and inter-day R.S.D. were below 15% for all the sample types. Recoveries averaged 83 and 95% for plasma and liver, respectively. The method is being successfully applied to determine rifampicin in plasma and liver samples taken during pharmacokinetic studies in rats.