Pharmacokinetics and vasodilating effect study of beraprost sodium in healthy volunteers.

Currently beraprost sodium (BPS) is widely proposed to ameliorate the symptoms caused by chronic arterial occlusive disease. The objective of this study is to investigate the BPS pharmacokinetic characteristics, its vasodilating effect and the relationship between plasma concentration vs response effect. 12 healthy Chinese volunteers (6 male, 6 female) were chosen to participate in a single center, random, and open design study.

Simultaneous determination of paraquat and diquat in human plasma by HPLC-DAD: Its application in acute poisoning patients induced by these two herbicides.

Background: Paraquat and diquat are widely used in agricultural production in many countries, which are very toxic to human beings. Paraquat can be detected in some diquat solution sold in the market. The blood concentration of paraquat or diquat is an important indicator for clinical diagnosis of paraquat or diquat poisoning.

Simultaneous Determination of Multiple Active Components from Bushen Pills and Application in a Pharmacokinetic Study in Rats.

Bushen Pills (BSPs), as a traditional Chinese medicine (TCM), is widely used in clinic to enrich Yang, nourish Yin, stem essence, and strengthen kidneys. Two chromatographic methods, liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), were applied to analyze the multiple active components of BSPs in dosage form for quality evaluation and in rat plasma for pharmacokinetics study, respectively. Three active constituents of BSPs, including paeoniflorin (PF), berberine hydrochloride (BBR), and schizandrin (SCH), were simultaneously determined by the established LC-MS method with electrospray ionization (ESI) in positive selected ion monitoring (SIM) mode at / 503.

Pharmacokinetic, metabolic profiling and elimination of brusatol in rats.

Brusatol, a quassinoid isolated from the traditional Chinese medicine Brucea javanica, has been reported to be an inhibitor of Nrf2 pathway and has great potential to be developed into a novel chemotherapeutic adjuvant. However, the in vivo process of brusatol has not been comprehensively explained yet. Therefore, this paper focused on the pharmacokinetic metabolism and excretion of brusatol in rats using a simple and reproducible LC-MS/MS method.

Pharmacokinetics and bioequivalence study of tetramethylpyrazine phosphate tablets after single-dose administration in healthy Chinese male subjects .

Background: Tetramethylpyrazine, isolated from Ligusticum wallichii Franch., is widely used for the treatment of cerebrovascular and cardiovascular diseases in China.

Objective: To assess and compare the pharmacokinetic characteristics and bioequivalence of two tetramethylpyrazine phosphate (TMPP) tablets in healthy Chinese male subjects.

A simple and economical method of gas chromatography-mass spectrometry to determine the presence of 6 pesticides in human plasma and its clinical application in patients with acute poisoning.

An economical, rapid, and sensitive method of gas chromatography-mass spectrometry (GC-MS) was developed and validated to determine the presence of six pesticides (dichlorvos, acetochlor, atrazine, chlorpyrifos, α-endosulfan, and β-endosulfan) in human plasma. The pesticides were extracted with acetonitrile and concentrated using anhydrous sodium sulfate. Then, the target compounds were analyzed and quantified with GC-MS using borneol as an internal standard.

Comparison of New Liquid Chromatography-Mass Spectrometry Method and Enzyme-Multiplied Immunoassay Technique for Routine Therapeutic Drug Monitoring of Vancomycin in Chinese Patients.

Background: Therapeutic drug monitoring of vancomycin is very valuable due to the good correlation between trough levels and clinical outcome. Therefore, it is important to accurately determine the concentration of vancomycin in patient plasma for adequate dose-adjustment. The objective of this study was to develop a new liquid chromatography-mass spectrometry (LC-MS) method for determination of vancomycin in patient plasma and compare the results with those obtained from enzyme-multiplied immunoassay technique (EMIT).

Comparison of the docetaxel concentration in human plasma measured with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and a nanoparticle immunoassay and clinical applications of that assay.

To determine the feasibility of using a nanoparticle immunoassay for clinical therapeutic drug monitoring (TDM) of docetaxel concentrations, a sensitive and simple method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established to measure the docetaxel concentration in human plasma and the results of LC-MS/MS and the immunoassay were compared. Docetaxel and paclitaxel (the internal standard, or IS) in human plasma were extracted through protein precipitation, separated on a Diamonsil C18 column (150 mm × 4.6 mm, 5 μm), ionized with positive ions, and detected with LC-MS/MS in multi-reaction monitoring (MRM) mode.

Simple, rapid and highly sensitive HPLC method for measurement of Lamotrigine in human plasma and its clinical applications.

Spikes in Lamotrigine concentrations levels and associated clinical toxicity may occur unpredictably. This study describes the development and validation of a simple, more rapid, highly sensitive and economical method for measuring Lamotrigine (LTG) concentration levels in human plasma using HPLC-UV and its clinical applications. Analyte from plasma was extracted with methanol (protein precipitation) and separated on the analytical column Diamonsil C (150mm×4.

Identification and characterization of human UDP-glucuronosyltransferases responsible for the in vitro glucuronidation of bergenin.

Glucuronidation plays critical role in the elimination of bergenin; however the metabolic mechanism of UDP-glucuronosyltransferases (UGTs) in the process remains to be investigated. In this study, the kinetics of bergenin glucuronidation by pooled human liver microsomes (HLMs) and 12 recombinat UGT isozymes were investigated. The glucuronidation of bergenin can be shown in HLMs with a Km value of 231.

In vivo metabolism study of bergenin in rats by HPLC-QTOF mass spectrometry.

Bergenin is the major component of Ardisia creanta sims and Rodgersia sambucifolia hemsl with many biological activities. Although bergenin has been used to treat human diseases in China for man years, there is no report regarding its metabolism. This is the first report to separate and identify the metabolites of bergenin in vivo.

Determination of the active metabolite of moguisteine in human plasma and urine by LC-ESI-MS method and its application in pharmacokinetic study.

In this study, a sensitive and reproducible electro-spray ionization liquid chromatography-mass spectrometry (LC-ESI-MS) method was established to determine the concentration of M1, the main active metabolite of moguisteine in human plasma and urine. The analysis was performed on a Diamonsil® C₁₈(2) column (150 mm × 4.6 mm, 5 μm) with the mobile phase consisting of 0.

Simultaneous determination of lercanidipine, benazepril and benazeprilat in plasma by LC-MS/MS and its application to a toxicokinetics study.

We aim to develop a rapid, simple, sensitive and specific LC-MS/MS method for the simultaneous quantification of lercanidipine, benazepril and benazeprilat in plasma. It is performed on the Agilent 6410 LC-MS/MS under the multiple-reaction monitoring (MRM) mode with electrospray ionization. Gliclazide was used as the internal standard (IS).

Determinations of mifepristone and its metabolites and their pharmacokinetics in healthy female Chinese subjects.

The aim of this study is to establish an HPLC method for simultaneous determinations of mifepristone and its metabolites, mono-demethylated mifepristone, di-demethylated mifepristone and C-hydroxylated mifepristone in plasma and to evaluate the pharmacokinetic characteristics of mifepristone tablet. Twenty healthy female Chinese subjects were recruited and a series of blood samples were collected before and after 0.25, 0.

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

A sensitive and selective liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of salbutamol in human plasma and urine, and successfully applied to the pharmacokinetic study of salbutamol in Chinese healthy volunteers after inhalation of salbutamol sulfate aerosol. Salbutamol and the internal standard (IS) acetaminophen in plasma and urine were extracted with ethyl acetate, separated on a C(18) reversed-phase column, eluted with mobile phase of acetonitrile-ammonium acetate (5 m m; 30:70, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor → product ions of m/z 240.2 → 148.

Separation and identification of norcantharidin metabolites in vivo by GC-MS method.

Norcantharidin (NCTD), the demethylated analogue of cantharidin, inhibits the proliferation of a variety of human tumor cell lines, and appears to cause the least nephrotoxic and inflammatory side effects. Although NCTD has been used to treat human cancers in China for years, there is no report regarding its metabolism up to now. This is the first report to separate and identify the main metabolites of NCTD in vivo by GC-MS using TMS derivatives.

Bioequivalence of nifedipine softgel and capsule in healthy Chinese volunteers by liquid chromatography-mass spectrometry.

The study aimed to compare and evaluate the bioequivalence of Calcigard-10 softgel and Adalat 10 capsule in healthy Chinese volunteers in a randomized, two-way cross over study design with a washout period of 7 days. A sensitive and reproducible electro-spray ionization liquid chromatography-mass spectrometry (ESI-LCMS) assay was developed and validated to determine nifedipine in human plasma using nitrendipine as internal standard. Nifedipine and nitrendipine were extracted from plasma using liquid-liquid extraction with methylene chloride as extraction solvent.

Metabolism and disposition of tribendimidine and its metabolites in healthy Chinese volunteers.

Background: Tribendimidine is a new anthelmintic agent synthesized by Chinese scientists. It is a broad spectrum agent with high activity against parasites. However, its disposition and metabolism remain unknown.

Determination and pharmacokinetic study of hydrocodone in human plasma by liquid chromatography coupled with tandem mass spectrometry.

A rapid, highly sensitive and specific high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS-MS) quantitation method was developed and validated for the determination of hydrocodone in human plasma. Sample was extracted from 0.5mL heparinized plasma by a simple liquid-liquid extraction method and analyzed on a C18 column with a mobile phase of acetonitrile-water (78:22,v/v,0.

Comparison of different pharmacodynamic models for pharmacokinetic-pharmacodynamic (PK-PD) modeling of carvedilol.

The paper is aimed to investigate the pharmacokinetic (PK) and the pharmacodynamic (PD) properties of carvedilol using indirect response and effect-compartment link models, and compare the fitness of PK-PD models. Twenty male healthy Chinese volunteers received a single oral dose of 20 mg of carvedilol. The plasma concentrations of carvedilol were determined by reversed-phase HPLC method with fluorescence detection, and the pharmacokinetic parameters were calculated by DAS2.

[HPLC-MS/MS method for determination of sodium cromoglycate concentration in human plasma and its pharmacokinetics].

The study established an HPLC-MS/MS method for determining the concentrations of sodium cromoglycate in human plasma and evaluated the pharmacokinetics of nasal drops and nasal spray. A C18 column was used to separate sodium cromoglycate in plasma with a mobile phase of a mixture of ammonium-methanol (involves 50% acetonitrile) (15:85) at a flow rate of 0.4 mL x min(-1).

Determination of bergenin in human plasma after oral administration by HPLC-MS/MS method and its pharmacokinetic study.

A highly sensitive, simple and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and applied to the determination of bergenin concentration in human plasma. Bergenin and the internal standard (IS) thiamphenicol in plasma were extracted with ethyl acetate, separated on a C(18 )reversed-phase column, eluted with mobile phase of acetonitrile-water, ionized by negative ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor --> product ions of m/z 327.1 --> 192 for bergenin and 354 --> 185.

Determination of betamethasone in human plasma by liquid chromatography with tandem mass.

A sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of betamethasone in human plasma. The analyte was isocratically eluted on a Venusil XBP C8 column (200 mm x 3.9 mm ID, 5 microm) with methanol-water mol x L(-1) ammonium formate) (80:20) at a flow rate of 0.

Determination of sodium cromoglycate in human plasma by liquid chromatography with tandem mass.

A sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of sodium cromoglycate (SCG) in human plasma after a nasal dose of 10.4 mg sodium cromoglycate nasal spray, using pravastatin sodium as the internal standard. The method was validated over a linear range of 0.

Determination and pharmacokinetic study of norcantharidin in human serum by HPLC-MS/MS method.

A sensitive, simple and selective high-performance liquid chromatography-tandem mass spectrometry method was developed and applied to the determination of norcantharidin concentration in human serum. Norcantharidin (NCTD) and cyclophosphamide (IS) in serum were extracted with acetone, separated on a C18 reversed-phase column, gradiently eluted with a mobile phase of acetonitrile-water containing 2 mm ammonium acetate and 0.1% formic acid (pH 3), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor-->product ions of m/z 169.