2011 Vol. 1, No. 4

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Liquid chromatography coupled with time-of-flight and ion trap mass spectrometry for qualitative analysis of herbal medicines
Xiao-Fei Chen, Hai-Tang Wu, Guang-Guo Tan, Zhen-Yu Zhu, Yi-Feng Chai
2011, 01(4): 235-245. doi: 10.1016/j.jpha.2011.09.008
Abstract:
With the expansion of herbal medicine (HM) market, the issue on how to apply up-to-date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOF-MS) and ion trap mass spectrometry (IT-MS) is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis (2006-2011). The advantages and future developments of LC coupled with IT and TOF-MS are highlighted.
Sensing of chlorpheniramine in pharmaceutical applications by sequential injector coupled with potentiometer
Tawfik A. Saleh
2011, 01(4): 246-250. doi: 10.1016/j.jpha.2011.09.002
Abstract:
This paper reports on development of a system consisting of a portable sequential injector coupled with potentiometric unit for sensing of chlorpheniramine (CPA), based on the reaction of CPA with potassium permanganate in acidic media. Various experimental conditions affecting the potential intensity were studied and incorporated into the procedure. Under the optimum conditions, linear relationship between the CPA concentration and peak area was obtained for the concentration range of 0.1-50ppm. The method reflects good recovery with relative standard deviation (RSD)<3%. The detection limit was 0.05 ppm. The developed method was successfully applied for determination of CPA in pure form and in pharmaceutical dosage forms. The results, obtained using the method, are in accord with the results of the British pharmacopoeia method. In addition to its accuracy and precision, the method has the advantages of being simple, inexpensive and rapid.
Development and validation of analytical method for the estimation of lamivudine in rabbit plasma
Akhilesh Vikram Singh, Lila K. Nath, Nihar R. Pani
2011, 01(4): 251-257. doi: 10.1016/j.jpha.2011.08.001
Abstract:
Lamivudine has been widely used in the treatment of HIV disease. A reliable, sensitive reversed phase high performance liquid chromatography (RP-HPLC) method was developed and validated for lamivudine in rabbit plasma. The method was developed on Hypersil BDS C-18 column (250 mm × 4.6 mm, 5 μm) using a mobile phase of 0.25% Triethylamine buffer (pH 3.0):acetonitrile (70:30, v/v). The efficient was monitored by UV detector at 256 nm. The total run time was 15 min with a flow rate of 1.0 mL/min. Calibration curve was linear over the concentration range of 25-2000 ng/mL. The retention times of lamivudine and internal standard (Nelfinavir) were 8.78 min and 10.86 min, respectively. The developed RP-HPLC method can be successfully applied for the quantitative pharmacokinetic parameters determination of lamivudine in rabbit model.
An ionic liquid supported CeO2 nanoparticles-carbon nanotubes composite-enhanced electrochemical DNA-based sensor for the detection of Pb2+
Yan Li, Xiao-Rong Liu, Xiao-Hui Ning, Can-Can Huang, Jian-Bin Zheng, Jun-Cai Zhang
2011, 01(4): 258-263. doi: 10.1016/j.jpha.2011.09.001
Abstract:
An electrochemical sensor incorporating a signal enhancement for the determination of lead (Ⅱ) ions (Pb2+) was designed on the basis of the thrombin-binding aptamer (TBA) as a molecular recognition element and ionic liquid supported cerium oxide (CeO2) nanoparticles-carbon nanotubes composite modification. The composite comprises nanoparticles CeO2, multi-wall carbon nanotubes (MWNTs)and hydrophobic room temperature ionic liquid (RTIL) l-ethyl-3-methylimidazolium tetrafluoroborate (EM1MBF4). The electrochemical sensors were fabricated by immersing the CeO2-MWNTs-EMIMBF4 modified glassy carbon electrode (GCE) into the solution of TBA probe. In the presence of Pb2+, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2+ and TBA. The TBA-bound Pb2+ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2+. The reduction peak current is linearly related to the concentration of Pb2+ from 1.0 × 10 8 M to 1.0 × 10-5 M with a detection limit of 5 × 109 M. This work demonstrates that the CeO2-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobilizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.
Screening of chemokine receptor CCR4 antagonists by capillary zone electrophoresis
Zhe Sun, Lin-Jie Tian, Qian Lin, Xiao-Mei Ling, Jun-Hai Xiao, Ying Wang
2011, 01(4): 264-269. doi: 10.1016/j.jpha.2011.09.010
Abstract:
CC chemokine receptor 4 (CCR4) is a kind of G-protein-coupled receptor, which plays a pivotal role in allergic inflammation. The interaction between 2-(2-(4-chloro-phenyl)-5-{[(naphthalen-1-ylmethyl)-carbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-N-(3-morpholin-4-yl-propyl)-acetamide (S009) and the N-terminal extracellular tail (ML40) of CCR4 has been validated to be high affinity by capillary zone electrophoresis (CZE). The S009 is a known CCR4 antagonist. Now, a series of new thiourea derivatives have been synthesized. Compared with positive control S009, they were screened using ML40 as target by CZE to find some new drugs for allergic inflammation diseases. The synthesized compounds XJH-5, XJH-4, XJH-17 and XJH-1 displayed the interaction with ML40, but XJH-9, XJH-10, XJH-11, XJH-12, XJH-13, XJH-14, XJH-3, XJH-8, XJH-6, XJH-7, XJH-15, XJH-16 and XJH-2 did not bind to ML40.Both qualification and quantification characterizations of the binding were determined. The affinity of the four compounds was valued by the binding constant, which was similar with the results of chemotactic experiments. The established CEZ method is capable of sensitive and fast screening for a series of lactam analogs in the drug discovery for allergic inflammation diseases.
Comparative pharmacokinetics of chlorogenic acid after oral administration in rats
Wei Qi, Ting Zhao, Wen-Wen Yang, Guang-Hou Wang, Hua Yu, Hai-Xiao Zhao, Chen Yang, Li-Xin Sun
2011, 01(4): 270-274. doi: 10.1016/j.jpha.2011.09.006
Abstract:
The present study was aimed at the comparison of the pharmacokinetics of pure chlorogenic acid and extract of Solanum lyratum Thunb. The animals were allocated to two groups, and were administered chlorogenic acid or extract of S. lyratum Thunb. at a dose of 50.0 mg/kg orally. Blood samples were collected up to 8 h post-dosing. Plasma chlorogenic acid analyses were performed using an HPLC method with UV detector. The pharmacokinetic parameters were evaluated using non-compartmental assessment. Significant differences existed in the two groups for AUC0-t, AUC0-∞ and CLz/F. The reliable HPLC method was successfully applied to the determination of chlorogenic acid in rat plasma at dosage of 50.0 mg/kg.
Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form
Deepak Bageshwar, Vineeta Khanvilkar, Vilasrao Kadam
2011, 01(4): 275-283. doi: 10.1016/j.jpha.2011.09.012
Abstract:
A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v). This system was found to give compact and dense spots for both itopride hydrochloride (Rf value of 0.55±0.02) and pantoprazole sodium (Rf value of 0.85 ± 0.04). Densitometric analysis of both drugs was carried out in the reflectance-absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9988± 0.0012 in the concentration range of 100-400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9990±0.0008 in the concentration range of 200-1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.
Simultaneous quantification of five major active components in capsules of the traditional Chinese medicine 'Shu-Jin-Zhi-Tong' by high performance liquid chromatography
Xing-Xin Yang, Xiao-Xia Zhang, Rui-Miao Chang, Yan-Wei Wang, Xiao-Ni Li
2011, 01(4): 284-290. doi: 10.1016/j.jpha.2011.08.002
Abstract:
A simple and reliable high performance liquid chromatography (HPLC) method has been developed for the simultaneous quantification of five major bioactive components in ‘Shu-Jin-Zhi-Tong' capsules (SJZTC), for the purposes of quality control of this commonly prescribed traditional Chinese medicine. Under the optimum conditions, excellent separation was achieved, and the assay was fully validated in terms of linearity, precision, repeatability, stability and accuracy. The validated method was applied successfully to the determination of the five compounds in SJZTC samples from different production batches. The HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of SJZTC.
Simultaneous determination of vitexin-2"-O-glucoside,vitexin-2"-O-rhamnoside, rutin, vitexin and hyperoside by HPLC
Chang-He Wang, Yu-Xuan Wang, Hai-Jing Liu
2011, 01(4): 291-296. doi: 10.1016/j.jpha.2011.09.003
Abstract:
A simple, precise, and rapid high-performance liquid chromatographic method was developed and validated for the simultaneous determination of vitexin-2"-O-glucoside, vitexin-2"-O-rhamnoside, rutin, vitexin, and hyperoside. The HPLC separation was performed using a Shim-pack VP-ODS C18 column (250 mm × 4.6 mm i.d. , 5 μm) with the isocratic mobile phase consisting of tetrahydrofuran/acetonitrile/0.05% phosphoric acid solution (20:3:77, v/v/v), and the flow rate was set at 1.0 mL/min. UV detection was carried out at a wavelength of 360 nm and the whole analysis took 25 min. The method was linear in the range of 4.12-206.00 μg/mL for vitexin-2"-O-glucoside, 4.05-202.50 μg/mL for vitexin-2"-O-rhamnoside, 1.64-82.00 μg/mL for rutin, 1.74-87.00 μg/mL for vitexin, and 1.41-70.60 μg/mL for hyperoside with the correlation coefficient for each analyte more than 0.998.The limit of detection (LOD) and limit of qnantitation (LOQ) were 0.6 and 2 ng for vitexin-2"-O-glucoside, 0.6 and 2 ng for vitexin-2"-O-rhamnoside, 0.3 and 1 ng for rutin, 1 and 3 ng for vitexin, and 0.5 and 2 ng for hyperoside, respectively. Lntra- and inter-day precision and accuracy (RSD) were less than 3%. The developed HPLC method was successfully applied to the analysis of five flavonoids in hawthorn leaves, hawthorn fruits, and the preparations containing hawthorn leaves or fruits.
Determination and pharmacokinetic study of catechin in rat plasma by HPLC
Li Xie, Xin-Nan Li, De-Xi Jiang, Dan Zhang
2011, 01(4): 297-301. doi: 10.1016/j.jpha.2011.09.004
Abstract:
A high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol- 5% aqueous zinc sulfate (70:30, v/v) as precipitant. Chromatographic separation was achieved on Hypersil C18 column (250 mm × 4.6 mm, 10 μm) with acetonitrile water triethylamine (6:94:0.3, v/v/v, pH 4.0±0.1, adjusted with phosphoric acid) as mobile phase, followed by a UV detection at 207 nm. Good linearity was obtained over the range of 0.143-7.15 mg/L of catechin, with correlation coefficient of 0.9992.The method was simple, sensitive, accurate and reproducible and has been successfully applied to the pharmacokinetic study of catechin in rat plasma.
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2011, 01(4): 302-318.
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