Determination and Pharmacokinetics of Clopidogrel in Human Plasma by LC-MS/MS / 医药导报

Objective To establish a liquid chromatography-tandem mass spectrometric ( LC-MS/MS ) for determination of clopidogrel in human plasma and stability of clopidogrel under different conditions,which was used subsequently to investigate the pharmacokinetics of clopidogrel in healthy Chinese volunteers. Methods Clopidogrel-d4 hydrogen sulfate was used as an internal standard. Separation was achieved on a WATERS Xterra? RP18 column (4.6 mm× 100 mm,3.5μm) with a mobile phase consisting of acetonitrile-0.1% formic acid (66:34) at a flow rate of 1.0 mL.min-1 within 3.2 min. ESI source was applied and operated in positive ion mode and multiple reaction monitoring (MRM). Plasma samples were pretreated by acetonitrile precipitation. Results A good linearity of clopidogrel was obtained in the concentration range of ( 5-5 000 ) ng.L-1. The lower limit of quantification was 5 ng.L-1. The intra-and inter-run precisions at three quality control levels were within 1.3%–9.9%,the relative deviation of the assay was within -6.2%-14.3%. The blood samples were stable when chilled with crushed ice ( 0℃) and cold water ( 4℃) ,as well as kept at room temperature ( 20℃) for 40 min. The plasma QC samples were stable at room temperature ( 20 ℃) for 4 h,at -70℃ for 38 days and during three freeze-thaw cycles. Hemolysis in blood sample drawn didn’ t affect the plasma concentration. The determination and the result of incurred sample reanalysis met the requirements. Conclusion A specific, rapid, sensitive and stable LC-MS/MS method is developed and validated for determination of clopidogrel in human plasma. The method is proven to be suitable for study of the pharmacokinetics of clopidogrel in healthy Chinese volunteers after a single oral dose of 75 mg clopidogrel hydrogen sulphate tablet.

Simultaneous quantitation of folic acid and 5-methyltetrahydrofolic acid in human plasma by HPLC-MS/MS and its application to a pharmacokinetic study☆ / 药物分析学报

A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active metabolite, 5-methyltetrahydrofolic acid (5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% (v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring (MRM) mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.

Pharmacokinetics of levosulpiride after single and multiple intramuscular administrations in healthy Chinese volunteers

The main purpose of this study was to evaluate the pharmacokinetics of levosulpiride in humans after single and multiple intramuscular injections. Six males and six females received single dose of either 25 mg or 50 mg levosulpiride, or multiple doses of 25 mg every 12 h for 5 consecutive days. In the single 25 mg study, the mean peak plasma concentration (C max) was 441 ng/mL, the mean area under the concentration-time curve from 0 to 36 h (AUC0-36) was 1724 ng h/mL, and the mean elimination half-life (t 1/2) was 7.0 h. In the single 50 mg study, the mean C max was 823 ng/mL, the mean AUC0-36 was 3748 ng·h/mL, and the mean t 1/2 was 6.8 h. After multiple doses of 25 mg levosulpiride, the average plasma concentration (C av) was 136 ng/mL, the fluctuation index (DF) was 3.60, and the accumulation ratio (R) was 1.2. Levosulpiride injections appeared to be well tolerated by the subjects, and can be used for successive administration.

Determination of Landiolol Concentration in Human Blood by LC-MS/MS / 医药导报

Objective To establish an LC-MS/MS method for the detection of landiolol concentration in human blood.Methods After pretreatment with neostigmine and a deproteinization procedure, landiolol and the internal standard venlafaxine were eluted isocratically using a mobile phase consisting of acetonitrile and 10 mmoL·L-1 ammonium acetate with 0. 1% formic acid in a ratio of 3664 ( V/V ) . Separation of the respective compounds was achieved on a Waters XTerra? RP18 column (150 mmí4. 6 mm,5 μm). Quantitative analysis of landiolol was conducted by a triple-quadrupole mass spectrometer with positive-electrospray ionization source,monitored under a multiple reaction monitoring ( MRM) mode. The extracted ions monitored following MRM transitions were m/z 510. 5→423. 1 for landiolol and m/z 278. 2→215. 1 for the internal standard venlafaxine. ResultsThe calibration curve of landiolol in human blood showed good linear relationship in the range of 1. 010-2 020 μg·L-1 . The lower limit of quantitation was 1. 010 μg · L-1 . The RSD of within-day and between-day precision was less than 6. 5% and 4. 8%, respectively. The recovery rate was 92. 6%-100. 9%. Conclusion The method is proven to be simple,rapid and reliable,and can be applied to study the pharmacokinetics of landiolol hydrochloride in healthy Chinese volunteers.

Drug Utilization in 690 Nationwide Sample Hospitals During 2005～2006 / 中国药房

OBJECTIVE:To evaluate the drug utilization in nationwide sample hospitals so as to provide information for the production, management and utilization of drugs. METHODS: The drug utilization data in nationwide 690 hospitals during the period 2005 ～2006 were analyzed statistically. RESULTS & CONCLUSION: Anti-infective drugs, cardiovascular drugs, biological products and biochemical drugs have been ranking among the first 3 places in consumption, but their consumption sum showed a downward trend. The consumption sum of anti-tumor drugs, Chinese formulated products, digestive system drugs, and respiratory system drugs showed an upward trend. The top 20 drugs on the list of consumption sum were mainly antibiotics. The consumption quantity and consumption sum of anti-tumor drugs showed an upward trend. Of the top 10 manufacturers in terms of consumption sum, the imported manufacturers took a small proportion while the joint venture took a higher proportion.

Analysis on the Status Quo and Tendency of TCM Injections in Our Hospital from 2006 to 2009 / 中国药房

OBJECTIVE:To analyze the status quo and tendency of TCM injection in our hospital. METHODS:Consumption sum,DDDs and DDDC of TCM injections in our hospital from 2006 to 2009 were analyzed statistically. RESULTS:The consumption sum of TCM injections increased year by year. The consumption sum of TCM injection was increased by 40.24% in 2007 and 32.66% in 2008 while it was decreased by 1.84% in 2009. The proportions of consumption sum of TCM injection in total consumption sum of drugs in 4 years were 2.59%,3.43%,3.98% and 3.30% respectively,showing yearly increasing trend. CONCLUSION:The application of TCM injection in our hospital shows a reasonable increase. Clinical pharmacists have rational reaction to ADR and adverse events caused by TCM injections.