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ABSTRACT: A sensitive, simple and specific high performance liquid chromatography-electro spray ionization mass spectrometry method was developed for the determination of ilaprazole in the plasma of beagles administered via i.v. bolus doses of ilaprazole. The procedure employed buspirone as the internal standard and a simple protein precipitation step. The separation was achieved using a C18 column (100 mm x 2.1 mm, 5 microm) with a mobile phase consisting of water-methanol-acetonitrile (69:8:23, v/v/v) containing 0.1% (v/v) formic acid at a flow rate of 0.2 mL/min. The detection was accomplished by a mass spectrometer using selected ion monitoring (SIM) in positive mode. The linearity was from 5 microg/L to 10,000 microg/L with a sensitivity of 5 microg/L as the lower limit of quantification. The inter- and intra- day precisions were within 9.00%. The mean recoveries at three spiked levels were about 106% and the matrix effects were less than 142.0%. The method described above was successfully applied to analyze the beagle plasma samples of ilaprazole in a pharmacokinetic study. The area under the plasma concentration-time curve (AUC(0-infinity) of ilaprazole after i.v. doses of 0.2, 0.8 and 3.2 mg/kg were (2.4 x 10(4) +/- 3 x 10(3)), (8.8 x 10(4) +/- 1.6 x 10(4)) and (5.4 x 10(5) +/- 8 x 10(4)) microg/L x min, respectively. On the basis of AUC, the pharmacokinetic property of ilaprazole was proposed to be linear dynamics.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 05/2012; 30(5):452-6.
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ABSTRACT: A sensitive and selective method for determination of (S,R)-penehyclidine in rat plasma by liquid chromatography-tandem mass spectrometry is described. The procedure employed the use
of an internal standard (I.S.) and a simple protein precipitation step. The method developed was linear from 0.1 to 100ng
mL−1, with a sensitivity of 0.1ng mL−1 as the lower limit of quantification. The intra- and inter-day assay accuracy (relative error) was within 8.27% and precision
(RSD) was below 6.7%. It was successfully applied to pharmacokinetic studies of (S,R)-penehyclidine in rat plasma.
KeywordsColumn liquid chromatography-LC-MS-MS-Pharmacokinetics-Anticholinergic drug-(S,R)-Penehyclidine
Chromatographia 04/2012; 71(11):1025-1030. · 1.20 Impact Factor
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ABSTRACT: Peramivir is a novel influenza neuraminidase inhibitor. In this article, hydrophilic interaction chromatography coupled with tandem mass spectrometry was developed to determine peramivir in human plasma. The positive ion MRM mode was performed and the precursor to the product ion transitions of m/z 329-->100 and 285-->138 were used to measure peramivir and Ro 64-0802 (I.S.). Chromatographic separation was performed on an Amide-80 column with acetonitrile-water-formic acid (70:30:0.1, v/v/v, 0.5mL/min). The method was linear over a concentration range of 10-10,000ng/mL. The average inter-day/intra-day precision values were 3.7+/-1.8% and 4.3+/-1.8%, respectively, while the accuracy values were 97.0+/-4.8%. This method has been successfully applied to Phase I of clinical research of peramivir.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 05/2009; 877(10):933-8. · 2.78 Impact Factor
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ABSTRACT: A sensitive and reproducible high-performance liquid chromatography (HPLC)-UV method for the determination of Z24, a tumorigenesis and angiogenesis inhibitor, has been developed and validated in mouse whole blood. Blood samples were extracted with ether, evaporated, and the residue was reconstituted in mobile phase. An aliquot was separated by isocratic reversed-phase HPLC on a Hypersil ODS-2 column and quantified using UV detection at 390 nm. The mobile phase was 50% (v/v) acetonitrile/water with a flow rate of 0.8 ml/min. A linear curve over the concentration range of 0.05-6 microg/ml (r(2)=0.9976) was obtained. The coefficient of the variation for the intra- and inter-day precision ranged from 3.0 to 10.9% and 5.7 to 10.3%, respectively. The absolute recovery of Z24 was 89.2-108.5%. The method is simple, economical and sufficient for in vivo pharmacokinetic studies on Z24. Nonlinear pharmacokinetics was found in mice at doses from 20 to 80 mg/kg.
Journal of Chromatography B 10/2008; 873(1):27-30. · 2.89 Impact Factor
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ABSTRACT: A simple, sensitive and reliable method was developed to determine simultaneously the concentrations of thienorphine and its metabolite thienorphine glucuronide conjugate in rat plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The metabolite was identified by MS: thienorphine glucuronide conjugate. Sample preparation involved protein precipitation with methanol. Analytes were separated on Finnigan BetaBasic-18 column (150 mm x 2.1mm i.d., 5 microm) using methanol: water: formic acid (56:44:0.1, v/v/v) as mobile phase at a flow rate of 0.2 ml/min. The method had a linear calibration curve over the concentration range of 0.1-50 ng/ml for thienorphine and 2-1000 ng/ml for thienorphine glucuronide conjugate, respectively. LOQ of thienorphine and thienorphine glucuronide conjugate was 0.1 and 2 ng/ml, respectively. The intra- and inter-batch precisions were less than 12% and their recoveries were greater than 80%. Pharmacokinetic data of thienorphine and its metabolite thienorphine glucuronide conjugate obtained with this method following a single oral dose of 3mg/kg thienorphine to rats were also reported for the first time.
Journal of Chromatography B 12/2007; 859(1):52-61. · 2.89 Impact Factor
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ABSTRACT: A sensitive and selective liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of serial chiral novel anticholinergic compounds of phencynonate in rat plasma. After a simple protein-precipitation using methanol, the post-treatment samples were separated on a CAPCELL UG120 column with a mobile phase of a mixture of methanol and water (35:65) containing 0.1% formic acid. The serial chiral analytes and internal standard (IS) were all detected by the use of selected reaction monitoring mode (SRM). The method of all serial chiral analytes developed was validated in rat plasma with a daily working range of 0.5-100 ng/ml with correlation coefficient, R(2) > or = 0.99 and a sensitivity of 0.5 ng/ml as lower limit of quantification, respectively. This method was fully validated for the accuracy, precision and stability studies for all serial chiral analytes. The method proved to be accurate and specific, and was applied to the pharmacokinetic study of serial chiral novel anticholinergic compounds of phencynonate in rat plasma.
Journal of Chromatography B 09/2007; 855(2):180-5. · 2.89 Impact Factor
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ABSTRACT: A sensitive and specific high-performance liquid chromatography-tandem mass spectrometry method (LC/ESI/MS) was developed and validated for the identification and quantification of the novel lead compound of anticholinergic drug thiencynonate in rat plasma. The analytes were determined using positive electrospray ionization mass spectrometry in the selected reaction ion monitoring (SRM). The chromatography separation was on BetaBasic-18 column (150 mm x 2.1 mm i.d., 3 microm). The mobile phase was composed of methanol-water (70:30, v/v), containing 0.5 per thousand formic acid, which was pumped at a flow rate of 0.2 ml/min. Phencynonate was selected as the internal standard (IS). Simultaneous MS detection of thiencynonate and IS was performed at m/z 364.4 (thiencynonate), m/z 358 (phencynonate), and the SRM of the two compounds were both at 156. Thiencynonate eluted at approximately 2.8 min, phencynonate eluted at approximately 2.9 min and no endogenous materials interfered with their measurement. Linearity was obtained over the concentration range of 1-100 ng/ml in rat plasma. The lower limit of quantification (LLOQ) was reproducible at 1 ng/ml in rat plasma. The precision measured was obtained from 2.47 to 9.28% in rat plasma. Extraction recoveries were in the range of 67.63-76.76% in plasma. This method was successfully applied to the identification and quantification of thiencynonate in pharmacokinetic studies.
Journal of Pharmaceutical and Biomedical Analysis 10/2006; 42(2):149-54. · 2.97 Impact Factor
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ABSTRACT: A sensitive and specific high-performance liquid chromatographic assay with electrospray ionization mass spectrometry detection (LC-ESI-MS) has been developed and validated for the identification and quantification of the novel anticholinergic drug phencynonate in rat blood and urine. The sample pretreatment involves basification and iterative liquid-liquid extraction with ethyl ether-dichloromethane (2:1, v/v) solution, followed by LC separation and positive electrospray ionization mass spectrometry detection. The chromatography was on BetaBasic-18 column (150 mm x 2.1mm i.d., 3 microm). The mobile phase was composed of methanol-water (85:15, v/v), containing 0.5 per thousand formic acid, which was pumped at a flow-rate of 0.2 ml/min. Thiencynonate was selected as the internal standard (IS). Simultaneous MS detection of phencynonate and IS was performed at m/z 358.4 (phencynonate), m/z 364 (thiencynonate), and the selected reaction ion monitoring (SRM) of the two compounds was at 156. Phencynonate eluted at approximately 5.25 min, thiencynonate eluted at approximately 5.10 min and no endogenous materials interfered with their measurement. Linearity was obtained over the concentration range of 1-100 ng/ml in rat blood and 1-500 ng/ml in rat urine. The lower limit of quantification (LLOQ) was reproducible at 1 ng/ml in both of rat blood and urine. The precision measured was obtained from 2.92 to 9.76% in rat blood and 4.17 to 9.76% in rat urine. Extraction recoveries were in the range of 69.57-79.49% in blood and 56.85-64.86% in urine. This method was successfully applied to the identification and quantification of phencynonate in pharmacokinetic studies.
Journal of Chromatography B 01/2006; 828(1-2):75-9. · 2.89 Impact Factor
