共查询到20条相似文献,搜索用时 15 毫秒
1.
Lara F. Tutunji Maha F. Tutunji Mamoun I. Alzoubi Manal H. Khabbas Adi I. Arida 《Journal of pharmaceutical and biomedical analysis》2010
A sensitive, specific and selective liquid chromatography/tandem mass spectrometric method has been developed and validated for the simultaneous determination of irbesartan and hydrochlorothiazide in human plasma. Plasma samples were prepared using protein precipitation with acetonitrile, the two analytes and the internal standard losartan were separated on a reverse phase C18 column (50 mm × 4 mm, 3 μm) using water with 2.5% formic acid, methanol and acetonitrile (40:45:15, v/v/v (%)) as a mobile phase (flow rate of 0.70 mL/min). Irbesartan and hydrochlorothiazide were ionized using ESI source in negative ion mode, prior to detection by multiple reaction monitoring (MRM) mode while monitoring at the following transitions: m/z 296 → 269 and m/z 296 → 205 for hydrochlorothiazide, 427 → 175 for irbesartan. Linearity was demonstrated over the concentration range 0.06–6.00 μg/mL for irbesartan and 1.00–112.00 ng/mL for hydrochlorothiazide. The developed and validated method was successfully applied to a bioequivalence study of irbesartan (300 mg) with hydrochlorothiazide (12.5 mg) tablet in healthy volunteers (N = 36). 相似文献
2.
Isabela Costa César José Antônio de Aquino Ribeiro Leonardo de Souza Teixeira Karini Bruno Bellorio Fernanda Crunivel de Abreu Josianny Mesquita Moreira Paula Rocha Chellini Gerson Antônio Pianetti 《Journal of pharmaceutical and biomedical analysis》2011
A liquid chromatography–electrospray ionization tandem mass spectrometry (HPLC–ESI-MS/MS) method for the simultaneous quantitation of artemether and lumefantrine in human plasma was developed and validated. Artesunate was used as an internal standard (IS). The analytes were extracted by a protein precipitation procedure and separated on a reversed-phase Zorbax SB-Ciano column with a mobile phase composed of methanol and 10 mM aqueous ammonium acetate containing 0.2% (v/v) acetic acid and 0.1% (v/v) formic acid. Multiple reaction monitoring was performed using the transitions m/z 316 → m/z 267, m/z 530 → m/z 348 and m/z 402 → m/z 267 to quantify artemether, lumefantrine and artesunate, respectively. Calibration curves were constructed over the range of 10–1000 ng/mL for artemether and 10–18,000 ng/mL for lumefantrine. The lower limit of quantitation was 10 ng/mL for both drugs. The mean R.S.D. values for the intra-run precision were 2.6% and 3.0% and for the inter-run precision were 3.6% and 4.6% for artemether and lumefantrine, respectively. The mean accuracy values were 102.0% and 101.2% for artemether and lumefantrine, respectively. No matrix effect was detected in the samples. The validated method was successfully applied to determine the plasma concentrations of artemether and lumefantrine in healthy volunteers, in a one-dose pharmacokinetic study, over the course of 11 days. 相似文献
3.
Yantong Sun Mingyuan Liu Jiwen Zhang Yao Jiang Weisong Yu John Paul Fawcett Jingkai Gu 《Journal of pharmaceutical and biomedical analysis》2009
A rapid and sensitive assay for trantinterol, a novel β2-adrenoceptor agonist, in human plasma has been developed. Samples containing the analyte and internal standard, clenbuterol, were analyzed by liquid chromatography–tandem mass spectrometry after liquid–liquid extraction with diethyl ether:dichloromethane (60:40, v/v). Separation was performed on a Venusil MP C18 column (50 mm × 4.6 mm, 5 μm) using methanol:1% formic acid (50:50, v/v) as mobile phase and monitored by multiple reaction monitoring of the precursor-to-product ion transitions of trantinterol at m/z 311.2 → 238.1 and clenbuterol at m/z 277.2 → 203.1. The total run time was only 1.5 min and the method was linear over the concentration range 1–1000 pg/mL with a lower limit of quantitation of 1 pg/mL. Intra- and inter-day precisions (relative standard deviation) were below 7% and 12%, respectively, with accuracy (relative error) below 8%. The method was successfully applied to a pharmacokinetic study involving oral administration of a 50 μg trantinterol tablet to healthy volunteers. 相似文献
4.
Ping Zhu Yu-Guan Wen Ji-Mei Chen Jian Zhuang Zhi-Ling Zhou Shao-Yi Zheng Ruo-Bin Wu Xue-Jun Xiao Cong Lu Rui-Xin Fan Hui-Ming Guo Xiao-Ping Fan 《Journal of pharmaceutical and biomedical analysis》2011
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. 相似文献
5.
Chao Zhang Lu Wang Yan Yang Yantong Sun Jie Zhang Guoqing Li Jingkai Gu 《Journal of pharmaceutical and biomedical analysis》2010
A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the determination of sarpogrelate in human plasma. One-step protein precipitation with acetonitrile was used to extract the analytes from the plasma. Sarpogrelate and tramadol (internal standard, I.S.) were separated on a Venusil MP-C18 column within 1.7 min, using acetonitrile:ammonium acetate (10 mM, pH 6.8) (55:45, v/v) as mobile phase at a flow rate of 1.2 mL/min with an approximately 1:1 split entering the mass spectrometer. Detection was performed on electrospray positive ionization mass spectrometry by multiple reaction monitoring of the transitions of sarpogrelate at m/z 430.3 → 135.3 and of I.S. at m/z 264.1 → 58.0. The assay was validated over the concentration range of 1–1000 ng/mL with a lower limit of quantitation (LLOQ) of 1 ng/mL using 50 μL of plasma. The intra- and inter-day precision (relative standard deviation, R.S.D.) were ≤6.4% and ≤5.4%, respectively, with accuracy (relative error, R.E.) in the range 0.5–3.6%. The method was successfully applied to a pharmacokinetic and bioequivalence study enrolling 22 Chinese volunteers administered sarpogrelate tablets. 相似文献
6.
The liquid chromatographic–tandem mass spectrometry method was developed for the accurate quantitation of metoprolol succinate (MET) and simvastatin (SIM) in human plasma which were obtained from the pharmacokinetic (PK) study. The sample purification and pre-concentration was performed by protein precipitation technique using propranolol hydrochloride as working internal standard (WIS). The chromatographic separation was achieved using an isocratic mobile phase consisting of a mixture of acetonitrile and 0.5% formic acid (90:10 (v/v), pH 3.5) flowing through C18 column at a flow rate of 0.2 ml/min. Electro spray ionization (ESI) with multiple reaction monitoring (MRM) was used to acquire mass spectra. Ions were monitored in positive mode and the mass transitions measured were m/z 268.1 → m/z 103.2, m/z 441.3 → m/z 325.1 and m/z 260.0 → m/z 129.5 for MET, SIM and WIS, respectively. An extensive pre-study method validation was carried out in accordance with USFDA guidelines. The linearity for the calibration curve in the concentration range of 1.0–500.0 and 0.1–20 ng/ml for MET and SIM, respectively and the lower limits of quantitations (LLOQ) were 1.0 and 0.1 ng/ml for MET and SIM, respectively. The method was successfully applied to a PK study on fixed dose combination (FDC) tablet containing MET and SIM in healthy human subjects. 相似文献
7.
Jun Zhang Min ChenWenzheng Ju Shijia LiuMeijuan Xu Jihong ChuTing Wu 《Journal of pharmaceutical and biomedical analysis》2010
A rapid and high sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for simultaneous determination of chlorogenic acid and cinnamic acid in human plasma was developed. The analytes and internal standard (IS), tinidazole, were extracted from human plasma via liquid/liquid extraction with ether–ethyl acetate (1:1, v/v) and separated on an Agilent Zorbax SB C18 column within 5 min. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring (MRM) and negative ion mode. The precursor to product ion transitions monitored for chlorogenic acid, cinnamic acid and IS were m/z 352.9 → 191.1, 146.8 → 103.1, 245.6 → 126.0, respectively. The assay was validated with linear range of 1.00–800.00 ng/mL for chlorogenic acid and 0.50–400.00 ng/mL for cinnamic acid. The intra- and inter-day precisions (RSD%) were within 9.05% for each analyte. The absolution recoveries were greater than 74.62% for chlorogenic acid and 76.21% for cinnamic acid. Each analyte was proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to a pharmacokinetic study of Mailuoning injection in 10 healthy volunteers. 相似文献
8.
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. 相似文献
9.
A simple and efficient HPLC/UV method for the simultaneous determination of six bioactive flavones, namely baicalein, baicalin, wogonin, wogonoside, oroxylin A and oroxylin A-7-O-glucuronide, has been developed and applied for their content determination in reference herb and proprietary traditional Chinese medicine (PTCM) products of Radix Scutellariae. The chromatographic separation was carried out on a Thermo C18 column and linear gradient elution was employed with a mobile phase containing acetonitrile and 20 mM sodium dihydrogen phosphate buffer (pH 4.6). All the analytes were detected by PDA detector at a wavelength of 270 nm. Contents of the analytes in Radix Scutellariae containing PTCM products in forms of capsule, soft capsule, tablet and dripping pill and the reference herb of Radix Scutellariae were analyzed by sonicator extraction with methanol and water mixture (80:20) containing 1 mM HCl for 30 min followed by HPLC analysis. Separation of the six analytes was achieved within 25 min with good linearity (R2 > 0.99). The R.S.D. of both the intra-day and inter-day precision for all the six analytes was below 10.14%. The accuracy at different concentrations was within the range of −7.83 to 4.06%. The extraction recovery was within the range of 89.22–107.33% for all the analytes. Contents of the six flavones were found to vary significantly among different products with glycosides, such as baicalin, wogonoside and oroxylin A-7-O-glucuronide, in much greater quantity than their corresponding aglycones. In addition to baicalin (18.54 ± 0.71%, w/w), the commonly used marker compound for Radix Scutellariae, wogonoside (3.54 ± 0.18%, w/w) and oroxylin A-7-O-glucuronide (2.84 ± 0.14%, w/w) also existed in abundant amount in the reference herb. Our findings suggested that wogonoside and oroxylin A-7-O-glucuronide should also be served as the chemical markers together with baicalin for the quality control of herbs and PTCM products of Radix Scutellariae. 相似文献
10.
Elevation of plasma total homocysteine concentrations were observed in levodopa/dopa decarboxylase inhibitor (DDI)-treated
patients with Parkinson’s disease (PD). Degradation of levodopa to 3-O-methyldopa via the enzyme catechol-O-methyltransferase (COMT) is a methyl group demanding reaction. It generates homocysteine from the methyl group donor methionine.
But there are inconsistent outcomes, as most investigators determined homocysteine after an overnight washout of levodopa.
They did not consider the acute effects of levodopa/DDI intake in relation with COMT inhibition on homocysteine bioavailability.
The purpose of this study is to measure levels of homocysteine, levodopa, and its metabolite 3-O-methyldopa in plasma after reiterated oral levodopa/DDI administration with and without the COMT-inhibitor entacapone (EN).
Sixteen PD patients received 100 mg levodopa/carbidopa three times on day 1 and with EN on day 2 under standardized conditions.
Homocysteine concentrations increased on day 1 and generally over the whole interval. No significant ascent of homocysteine
appeared on day 2 only. Levodopa bioavailability was higher on day 2 due to the COMT inhibition. No change of 3-O-methyldopa appeared between both days. The correlation coefficients between homocysteine, levodopa, and 3-O-methyldopa were higher on day 1 than on day 2. Rise of homocysteine does not only depend on the oral levodopa dose, but also
on the acute intake of levodopa/DDI with or without COMT inhibition. Measurements of homocysteine should consider acute repeated
levodopa/DDI applications, as homocysteine and metabolically related 3-O-methyldopa accumulate due to their long plasma half-life in contrast to short-living levodopa. 相似文献
11.
Shuang-Qing Zhang Yi-Ning Song Xin-Hua He Bo-Hua Zhong Zhen-Qing Zhang 《Journal of pharmaceutical and biomedical analysis》2010
A specific and sensitive liquid chromatography–tandem mass spectrometric method for quantitative determination of paclitaxel in rat plasma was developed and validated using docetaxel as an internal standard. Liquid-liquid extraction using tert-butyl methyl ether was used to extract the drug and the internal standard from plasma. The separation of paclitaxel was performed on a C18 column with a mobile phase of acetonitrile:water:formic acid (65:35:0.1, v/v/v) over 5 min. The assay was based on the selected reaction monitoring transitions at m/z of the precursor-product ion transitions m/z 854.2 → 286.1 for paclitaxel and 808.3 → 527.2 for internal standard. The lower limit of quantification was 0.5 ng/mL based on 100 μL of plasma. Intra- and inter-day assay variations were less than 15%, and the accuracy values were between 95.4 and 105.4%. The extraction recoveries ranged from 96.7 to 103.7% across the calibration curve range. The method was successfully applied to measurement of low concentrations of paclitaxel or regenerated paclitaxel in plasma after intravenous administration of a single dose (10 mg/kg) of a poly(l-glutamic acid)-alanine-paclitaxel conjugate to rats. 相似文献
12.
Jifeng Gu Nianzu Chen Guoqiang Ding Zhen Zhang 《Journal of pharmaceutical and biomedical analysis》2011
A sensitive method for the quantification of oxaceprol in rat plasma using high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed. Sample pretreatment involved a simple protein precipitation by the addition of 60 μL of acetonitrile–methanol (1:2, v/v) to 20 μL plasma sample volume. Separation was achieved on a Dikma ODS-C18 (5 μm, 150 mm × 4.6 mm) reversed-phase column at 40 °C with acetonitrile/0.1% formic acid–4 mM ammonium acetate in water (35:65,v/v) at a flow rate of 0.6 mL/min. Detection was performed using an electrospray ionization (ESI) operating in negative ion multiple reaction monitoring (MRM) mode by monitoring the ion transitions from m/z 172 → 130 (oxaceprol) and m/z 153 → 109 (protocatechuic acid, internal standard). The calibration curve of oxaceprol in plasma showed good linearity over the concentration range of 1.25–800 ng/mL. The limit of detection and limit of quantification were 0.400 ng/mL and 1.25 ng/mL, respectively. Intra- and inter-day precisions in all samples were within 15%. There was no matrix effect. The validated method was successfully applied to a preclinical pharmacokinetic study of oxaceprol in rats. After oral administration of 20 mg/kg oxaceprol to rats, the main pharmacokinetic parameters Tmax, Cmax, T1/2, Vz/F and AUC0–t were 1.4 h, 1.2 μg/mL, 2.3 h, 19.7 L/kg and 3.4 mg h/L, respectively. 相似文献
13.
M. Contin R. Riva P. Martinelli F. Albani A. Baruzzi 《European journal of clinical pharmacology》1998,54(4):303-308
Objective: The aim of the study was to assess the effect of the time of ingestion of a meal on the pharmacokinetics and pharmacodynamics
of a levodopa/carbidopa controlled-release formulation in parkinsonian patients on chronic levodopa therapy.
Methods: The kinetic-dynamic profile of one tablet of controlled-release levodopa/carbidopa 200/50 mg was monitored in eight patients,
according to an intrasubject randomized cross-over design in two different sessions. A standard meal was consumed by the patients
after they had fasted for 15–17 h, on one occasion 30 min before the ingestion of the test dose, and on the other occasion
2 h after the ingestion of the same drug dose. Blood venous samples for analysis of plasma levodopa and its metabolite 3-O-methyldopa were drawn at 20-min intervals up to 6 h after dosing. Motor response to the levodopa test dose was assessed by
the finger tapping and walking speed tests at the same times as blood was drawn.
Results: Controlled is release levodopa intake after meals resulted in a significant delay in drug absorption, with an almost twofold
increase in time of initial appearance of levodopa in plasma and time to peak plasma concentration. Peak plasma drug concentrations
were not significantly different in the two experimental conditions; the area under the 6-h plasma concentration-time curve
showed an average reduction of 24% in the fed condition, partly reflecting the incomplete assessment of levodopa absorption,
within the 6 h of examination, due␣to 5-h delayed peak plasma levodopa concentration␣in two patients. With reference to levodopa
pharmacodynamics, time to onset of motor response was significantly delayed and duration of motor response significantly curtailed
in the fed condition, while the magnitude and overall extent of motor effect were unchanged.
Conclusions: In keeping with previous findings on levodopa standard-release preparations, these data show that time of meal ingestion
is an important determinant of levodopa disposition, even from controlled-release preparations in parkinsonian patients. From
a clinical point of view, these results help to explain some of the delayed, curtailed and even lacking responses that often
complicate afternoon motor performances in patients at the more advanced stages of the disease.
Received: 17 July 1997 / Accepted in revised form: 24 February 1998 相似文献
14.
A simple, rapid, sensitive and selective liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of azithromycin in rabbit conjunctiva tissues using roxithromycin as internal standard. Following a deproteinization procedure, the samples were eluted isocratically at a flow rate of 0.3 mL/min utilizing a mobile phase containing of 10 mM ammonium acetate (adjusted pH to 5.2 with 0.1% acetic acid)–methanol (18:82, v/v) and a SHISEIDO CAPCELL PAK C18 (3.0 mm × 75 mm, 3 μm). Azithromycin and its internal standard were measured by a triple-quadrupole mass spectrometer in the selected reaction monitoring (SRM) mode with precursor-to-product qualifier transition m/z 375 [M+2H]2+ → 591 and m/z 837 [M+H]+ → 679 respectively. The method demonstrated that good linearity ranged from 10 to 2000 ng/mL with r = 0.9998. The lower limit of quantification for azithromycin in conjunctiva tissues was 10 ng/mL with good accuracy and precision. The intra- and inter-day precision (RSD) values were below 15% and accuracy (%) ranged from 90% to 110% at all QC levels. The method was applicable to ocular pharmacokinetic studies of azithromycin. 相似文献
15.
Guixiang Pan Xiaoming Wang Yuhong Huang Xiumei Gao Yuefei Wang 《Journal of pharmaceutical and biomedical analysis》2010
A simple, sensitive and rapid LC–MS/MS method has been developed and validated for the identification and quantification of bivalirudin in human plasma using nafarelin as the internal standard. Following protein precipitation with methanol, the analytes were separated on a C18 column interfaced with a triple-quadrupole tandem mass spectrometer using positive electrospray ionization. Quantification of bivalirudin was conducted by multiple reaction monitoring (MRM) of the transitions of m/z 1091.4 → (356.4 + 227.4) for bivalirudin and m/z 662.4 → 328.5 for IS. The lower limit of quantification was 1.25 ng/ml, and the assay exhibited a linear range of 1.25–500 ng/ml. The developed assay method was successfully applied to a pharmacokinetic (PK) study in healthy volunteers after intravenous administration of bivalirudin. 相似文献
16.
Dag Nyholm Per Odin Anders Johansson Krai Chatamra Charles Locke Sandeep Dutta Ahmed A. Othman 《The AAPS journal》2013,15(2):316-323
Motor complications of Parkinson’s disease (PD) are a consequence of pulsatile dopaminergic stimulation from standard oral levodopa therapy. Levodopa–carbidopa intestinal gel (LCIG) is infused continuously via an intrajejunal percutaneous gastrostomy tube. This was the first study designed to characterize the full pharmacokinetic profiles of levodopa, carbidopa, and levodopa metabolite, 3-O-methyldopa (3-OMD) with 16-h LCIG infusion. Nineteen advanced PD patients (mean age, 65 years) who were on LCIG therapy for ≥30 days were enrolled. Patients received their individualized LCIG infusion doses, and serial pharmacokinetic samples were collected. Eighteen patients completed the study; 19 were assessed for safety. Mean (SD) total levodopa and carbidopa doses were 1,580 (403) and 395 (101) mg, respectively. Mean (SD) Cavg (μg/mL) were 2.9 (0.84) for levodopa, 17.1 (4.99) for 3-OMD, and 0.22 (0.08) for carbidopa. The degree of fluctuation [defined as (Cmax − Cmin)/Cavg] in levodopa, 3-OMD, and carbidopa plasma concentrations was very low (0.52, 0.21, and 0.96, respectively) during hours 2–16 of infusion. Accordingly, the within-subject coefficients of variation in levodopa, 3-OMD, and carbidopa concentrations were low (13%, 6%, and 19%, respectively). Three patients (16%) reported ≥1 treatment-emergent adverse event; none were considered severe. Continuous intrajejunal LCIG infusion maintained stable plasma levodopa levels over 16 h. Consistent exposure has been shown to reduce motor and nonmotor complications associated with oral medications. LCIG was well tolerated, consistent with previous reports. 相似文献
17.
Huaying Chen Yang Lin Min Han Shugong Bai Shaojun Wen 《Journal of pharmaceutical and biomedical analysis》2010
A fast and sensitive method to quantify fasudil hydrochloride (FH) and its active metabolite hydroxyfasudil (M3) in human plasma using HPLC–MS/MS has been developed and validated in present study. The method involved simple sample preparation with methanol as protein precipitation (3:1, v/v) and ranitidine as an internal standard (IS). The analytes and IS were separated using a gradient elution procedure on the analytical column ZORBAX StableBond-C18 (5 μm, 150 mm × 4.6 mm). Detection was performed by an AB 3200 QTRAP tandem mass spectrometer equipped with a Turbo IonSpray ionization source set in positive ion mode. Multiple reaction monitoring (MRM) using the precursor to product ion was m/z 292.2/99.2 for fasudil, m/z 308.2/99.2 for M3 and m/z for 315.3/176.2 for IS. The linear range of the method was from 0.4 to 250 ng/mL for both fasudil and M3. The lower limit of quantification was 0.4 ng/mL for both fasudil and M3. The intra- and inter-day relative standard deviation over the entire concentration range was less than 7.11% for fasudil and 10.6% for M3, respectively. The validated method was successfully applied for the evaluation of pharmacokinetic of fasudil hydrochloride after administration of 30 mg fasudil hydrochloride by continuous intravenous infusion over 30 min in 12 healthy Chinese volunteers. 相似文献
18.
Hai-Qiang Huang Xi Zhang Zhi-Xiu Xu Juan Su Shi-Kai Yan Wei-Dong Zhang 《Journal of pharmaceutical and biomedical analysis》2009
A rapid resolution liquid chromatography coupled with evaporative light scattering detection method was established for simultaneous determination of six saikosaponins, namely saikosaponin a, saikosaponin c, saikosaponin d, 6″-O-acetylsaikosaponin a, 3″-O-acetylsaikosaponin d and 6″-O-acetylsaikosaponin d in Bupleurum. The analysis was performed by using an Agilent Zorbax SB-C18 column (1.8 μm, 3.0 mm × 50 mm i.d.) at gradient elution of water and acetonitrile, and the saikosaponins were well separated within 12 min, which provided about a fourfold reduction in analysis time by comparing a conventional high performance liquid chromatography method. Owing to their low ultraviolet absorption, the saikosaponins were detected by evaporative light scattering. The standard curves to quantify the saikosaponins were constructed by the log–log plot, which showed good linearity with the correlation coefficients exceeding 0.9954. The detection limits and quantification limits ranged in 8.38–25.00 μg/mL and 25.13–45.00 μg/mL, respectively. Satisfactory intra-day and inter-day precisions were achieved with the relative standard deviation (R.S.D.) less than 6.58%, and the average recoveries obtained were in the range of 96.9–100.4%. In addition, MeOH–1.0% (v/v) pyridine was found to be the best the extraction solvent when compared to MeOH and MeOH–1.0% (v/v) ammonia water. A total of 23 samples of roots of Bupleurum from different species or locations were examined with this analytical method, and their chemical profiles provided information for the chemotaxonomic investigation. The results demonstrated that the analytical method is highly effective for the quality evaluation of Bupleurum species. 相似文献
19.
Wei Bu Xiaoqing FanHolly Sexton Irwin Heyman 《Journal of pharmaceutical and biomedical analysis》2010
Due to severe chelating effect caused by N-hydroxylpyridone group of ciclopirox, there is no published direct HPLC or LC/MS/MS method for the determination of ciclopirox in any in vitro or in vivo matrix. Instead, the time-consuming pre-column derivatization methods have been adapted for indirect analysis of ciclopirox. After overcoming the chelating problem by using K2EDTA coated tubes, a direct, sensitive and high-throughput LC/MS/MS method was successfully developed and validated to determine the amount of ciclopirox that penetrated across the nail plate during in vitro nail penetration studies. The method involved adding a chemical analog, chloridazon as internal standard (IS) in K2EDTA coated tubes, mixing IS with ciclopirox in a 96-well plate and then proceeding to LC/MS/MS analysis. The MS/MS was selected to monitor m/z 208.0 → 135.8 and 221.8 → 77.0 for ciclopirox and IS, respectively, using positive electrospray ionization. The method was validated over a concentration range of 8–256 ng/mL, yielding calibration curves with correlation coefficients greater than 0.9991 with a lower limit of quantitation (LLOQ) of 8 ng/mL. The assay precision and accuracy were evaluated using quality control (QC) samples at three concentration levels. Analyzed concentrations ranged from 101% to 113% of their respective nominal concentration levels with coefficients of variation (CV) below 10.6%. The average recovery of ciclopirox from nail matrix was 101%. 相似文献
20.
Jiangbin Han Shuang Jiang Xiangyong Cui Yantong Sun Guoqing Li Jiwen Zhang J. Paul Fawcett Jingkai Gu 《Journal of pharmaceutical and biomedical analysis》2009
A rapid and sensitive method based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) has been developed for the determination of octahydroaminoacridine in human plasma using tramadol as internal standard (I.S.). Sample preparation involved pH adjustment with sodium carbonate followed by solvent extraction with dichloromethane:ethyl ether (40:60, v/v). Chromatographic separation was achieved on a Venusil MP-C18 column (5 μm, 100 mm × 4.6 mm) using acetonitrile:10 mM ammonium acetate:formic acid (30:70:1, v/v/v) as mobile phase. Detection utilized an API 4000 system operated in the positive ion mode with multiple reaction monitoring of the analyte at m/z 203.1 → 175.1 and of the I.S. at m/z 264.1 → 58.0. The method was linear in the range 0.01–10 ng/ml with a lower limit of quantitation of 0.01 ng/ml. Intra- and inter-day precisions measured as relative standard deviation were <3.15% and <5.01%, respectively. The method was successfully applied to a pharmacokinetic study involving oral administration of a tablet containing 4 mg octahydroaminoacridine succinate to healthy volunteers. Pharmacokinetic parameters for octahydroaminoacridine include Cmax 1.19 ± 0.53 ng/ml, Tmax 0.77 ± 0.17 h, AUC0−t 3.42 ± 1.01 ng h/ml and t1/2 2.89 ± 0.56 h. 相似文献