LC–MS/MS Determination of Apigenin in Rat Plasma and Application to Pharmacokinetic Study

Background: A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method had been developed for the quantification of acotiamide in rat plasma and been applied to pharmacokinetic studies. However, there was no LC-MS/MS method been developed for the determination of acotiamide in human plasma and its pharmacokinetic study. Objective: A simple and fast LC-MS/MS method was established and validated for the quantification of acotiamide in human Received: plasma and was applied to a pharmacokinetic study. Methods: Sample preparation was accomplished Revised: Accepted: through protein precipitation, and chromatographic separation was achieved on a Welch, Ultimate XB-C18 column (2.1×50 mm, 3 μm) with a security guard cartridge C18 using a binary gradient with DOI: mobile phase A (Methanol) and B (the solution of 10 mM Ammonium acetate with 0.1% Formic acid) at a flow rate of 400 Results: The retention time of acotiamide and its internal standard, acotiamide-d6 was 1.78 min and 1.79 min, respectively. The total run time was 4.0 min. The method was developed and validated over the concentration range of 0.500-100 ng/mL for acotiamide, with correlation coefficient greater than 0.9987. The extraction recovery was more than 108.43% and the matrix effect was not significant. The inter- and intra-day precisions were below 5.80% and accuracies ranged from 92.7 to 103.0%. Acotiamide was demonstrated to be stable in human plasma under the tested conditions. Conclusion: The validated LC-MS/MS method was successfully applied to study the pharmacokinetic profiles of acotiamide in human plasma after oral administration and has achieved satisfactory results.

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A HPLC-DAD-MS/MS Method for Simultaneous Determination of Six Active Ingredients of Salviae Miltiorrhizae and Ligustrazine Hydrochloride Injection in Rat Plasma and its Application to Pharmacokinetic Studies

Current Drug Metabolism ◽

10.2174/1389200221999200819143230 ◽

2020 ◽

Vol 21 ◽

Author(s):

Jianyang Pan ◽

Luquan Zhang ◽

Difeifei Xiong ◽

Bailing Li ◽

Haibin Qu

Keyword(s):

Simultaneous Determination ◽

Pharmacokinetic Study ◽

Rat Plasma ◽

Array Detector ◽

Pharmacokinetic Studies ◽

Plasma Samples ◽

Active Ingredients ◽

Salviae Miltiorrhizae ◽

Salvianolic Acids

Aims: Pharmacokinetic Study of Salviae Miltiorrhizaeand Ligustrazine Hydrochloride injection. For the evaluation of mechanism of action, safety and clinical rational use of Salviae Miltiorrhizae and Ligustrazine Hydrochloride injection. Background: Salviae Miltiorrhizae and Ligustrazine Hydrochloride injection is a compound preparation consisted of Salvia Miltiorrhiza extract and ligustrazine hydrochloride for the treatment of cardiovascular and cerebrovascular diseases in China. Methods: Plasma samples were precipitated with methanol, which was spiked with ascorbic acid and the supernatant was separated on a Waters Cortecs C18 column, by using a gradient mobile phase system of acetonitrile-water containing 0.05% formic acid (v/v). For internal standards, puerarin was selected for the five salvianolic acids, while isofraxidin was used for ligustrazine hydrochloride. Besides, electrospray ionization in negative mode and multiple-reaction monitoring were used to identify and quantify the five salvianolic acids, whereas ligustrazine hydrochloride was quantified at 310 nm using the diode array detector. Results: Noticeably, all calibration curves showed good linearity (R2>0.99) over the concentration range, with a lower limit of quantification between 0.00411 and 0.0369μg/mL for salvianolic acids, and 1.74 μg/mL for ligustrazine hydrochloride. Next, the precision of the developed method was evaluated by intra-and inter-day assays, and the percentage of relative standard deviation was within 10%. Although the extraction efficiency of some salvianolic acids were not very satisfactory, the sensitivity of the analytical method met the analysis requirements of rat plasma samples. Moreover, the validated method was successfully applied to a pharmacokinetic study of Salviae Miltiorrhizae and Ligustrazine Hydrochloride injection in the rat model. Conclusion: Linear pharmacokinetic characteristics were observed for the six active ingredients after intravenous infusion administration in rats, within the dose range examined here. In summary, our study proposed a HPLC-DAD-MS/MS method in the simultaneous determination of multiple ingredients, and demonstrated its applicability in pharmacokinetic studies.

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DETERMINATION OF Cu(II) CONCENTRATION IN AQUEOUS MEDIUM USING INVERSION ELECTROCHEMICAL METHOD

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.85.9.2019.58-64 ◽

2019 ◽

Vol 85 (9) ◽

pp. 58-64

Author(s):

Vera Vorobets ◽

Gennadii Kolbasov ◽

Sergii Fomanyuk ◽

Nataliia Smirnova ◽

Oksana Linnik

Keyword(s):

Formic Acid ◽

Ammonium Acetate ◽

Copper Ions ◽

Stripping Voltammetry ◽

Acetate Buffer ◽

Background Solution ◽

Ammonium Acetate Buffer ◽

Photoelectrochemical Method ◽

Determination Of Copper

Electrode materials based on titanium dioxide modified with zinc ions and gold nanoparticles, synthesized by sol-gel method, were used to determine the concentration of Cu (II) in liquids by stripping voltammetry method. Determination of Cu (II) was done using background solutions based on 0.4 M formic acid and ammonium acetate buffer (pH = 7.5) using the standard addition method with a potential scanning speed of 50 mV•s-1. The solution was stirred during the preliminary electrolysis at a potential of -1400 mV (vs silver-chloride reference electrode) for 120 seconds and then the potential was scanned from -1200 mV to + 200 mV. It is shown that the background solution based on ammonium acetate buffer provides a higher sensitivity and a good selectivity of peaks for the determination of copper compared to the background solution based on formic acid. Determined that value of the analytical signal of copper in the studied model solutions based on ammonium acetate and formic acid is proportional to the concentration of copper ions in the solution. To increase the selectivity of stripping voltammetry method in determining copper concentrations in solutions, an inversion spectral photoelectrochemical method was proposed, the essence of which is preliminary electroconcentration of the elements under investigation in the cathode potential region and subsequent measurement of the spectral photoelectrochemical characteristics of electroconcentration products. It has been found that in solutions of 1M ammonium acetate containing Cu2+ ions, the cathodic polarization of TiO2-based photoelectrode leads to the appearance of a cathode photocurrent and the values of photocurrent quantum yield increase with increasing content of copper ions in the solution. The spectral sensitivity of the surface layer corresponds to the absorption spectrum of Cu2O. The sensitivity of stripping voltammetry method to copper Cu (II) using the materials studied was 0.3 mg•l-1. It is shown that the inversion photoelectrochemical method is promising in the selective determination of copper concentration in liquids.

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Development of a HPLC-MS/MS Method to Determine the 13 Elements of Semen Cuscutae and Application to a Pharmacokinetic Study in Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/6518528 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Jiayuan Shen ◽

Qi Jia ◽

Xuhua Huang ◽

Guangzhe Yao ◽

Wenjuan Ma ◽

...

Keyword(s):

Pharmacokinetic Study ◽

High Performance ◽

Rat Plasma ◽

Pharmacokinetic Parameters ◽

Plasma Samples ◽

Mobile Phases ◽

Relative Standard ◽

Liquid Chromatography Tandem Mass ◽

Interday Precision

This study developed a method for simultaneous determination of 13 elements of Semen Cuscutae (quercitrin, quercetin, hyperoside, caffeic acid, chlorogenic acid, luteolin, apigenin, kaempferol, isoquercitrin, cryptochlorogenic acid, isorhamnetin-3-O-glucoside, astragalin, and rutin) in rat plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in the negative MRM mode. The analytes were analyzed with CORTECS®C18 column (4.6 × 150 mm, 2.7 μm) with mobile phases consisting of 0.1% formic acid in water (A) and acetonitrile (B). The intra- and interday precision of the target compounds were expressed as relative standard deviation (RSD) in the range of 0.5%–10.4%, and the accuracy of the target compounds was expressed as relative error (RE) not exceeding ±14.5% for all analytes. In the meantime, the extraction recovery of the target compounds in plasma samples ranged from 87.4% to 106.2% and matrix effect from 81.0% to 115.5%. The established method was successfully accomplished for the pharmacokinetic study of the analytes in rat plasma samples following oral administration of Semen Cuscutae extract, and the pharmacokinetic parameters of seven compounds were obtained.

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HPLC Method Determination of Isoliquiritin Apioside and Isoliquiritin in Rat Plasma for Application in Pharmacokinetic Study after an Oral Administration of Zhigancao Extract

Journal of Analytical Methods in Chemistry ◽

10.1155/2012/364013 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Yan-yun Yang ◽

Liang Xu ◽

Song-yao Hao ◽

Yan Li ◽

Zhen-Qiu Zhang

Keyword(s):

Oral Administration ◽

Pharmacokinetic Study ◽

Mobile Phase ◽

Internal Standard ◽

Rat Plasma ◽

Hplc Method ◽

Plasma Samples ◽

Limit Of Quantification ◽

Precision And Accuracy

A sensitive HPLC method was developed for the quantitative determination of isoliquiritin apioside (ILA) and isoliquiritin (IL) in rat plasma. After protein precipitation with acetonitrile, chloroform was used to separate lipid-soluble impurities from the plasma samples and remove acetonitrile. A chromatography was carried out on Diamonsil C18 (150×4.6 mm; 5 μm) analytical column, using a mobile phase consisting of water (containing phosphoric acid 0.1%, v/v); acetonitrile (72 : 28, v/v) at a flow rate of 1.0 mL/min. The wavelength-switching technology was performed to determine ILA and IL at 360 nm and wogonoside (internal standard, IS) at 276 nm. The calibration curves of ILA and IL were fairly linear over the concentration ranges of 0.060–3.84 μg/mL (r=0.9954) and 0.075–4.80 μg/mL (r=0.9968), respectively. The average extract recoveries of ILA, IL, and IS were all over 80%. The precision and accuracy for all concentrations of quality controls and standards were within 15%. The lower limit of quantification (LLOQ) was 0.060 μg/mL for ILA and 0.075 μg/mL for IL. The method was used in pharmacokinetic study after an oral administration of Zhigancao extract to rats.

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DETERMINATION OF CU(II) CONCENTRATION IN AQUEOUS MEDIUM USING INVERSION ELECTROCHEMICAL METHOD

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.85.7.2019.24-30 ◽

2019 ◽

Vol 85 (7) ◽

pp. 24-30

Author(s):

Vera Vorobets ◽

Gennadii Kolbasov ◽

Sergii Fomanyuk ◽

Nataliia Smirnova ◽

Oksana Linnik

Keyword(s):

Formic Acid ◽

Ammonium Acetate ◽

Copper Ions ◽

Stripping Voltammetry ◽

Acetate Buffer ◽

Background Solution ◽

Ammonium Acetate Buffer ◽

Photoelectrochemical Method ◽

Determination Of Copper

Electrode materials based on titanium dioxide modified with zinc ions and gold nanoparticles, synthesized by sol-gel method, were used to determine the concentration of Cu (II) in liquids by stripping voltammetry method. Determination of Cu (II) was done using background solutions based on 0.4 M formic acid and ammonium acetate buffer (pH = 7.5) using the standard addition method with a potential scanning speed of 50 mV•s-1. The solution was stirred during the preliminary electrolysis at a potential of -1400 mV (vs silver-chloride reference electrode) for 120 seconds and then the potential was scanned from -1200 mV to + 200 mV. It is shown that the background solution based on ammonium acetate buffer provides a higher sensitivity and a good selectivity of peaks for the determination of copper compared to the background solution based on formic acid. Determined that value of the analytical signal of copper in the studied model solutions based on ammonium acetate and formic acid is proportional to the concentration of copper ions in the solution. To increase the selectivity of stripping voltammetry method in determining copper concentrations in solutions, an inversion spectral photoelectrochemical method was proposed, the essence of which is preliminary electroconcentration of the elements under investigation in the cathode potential region and subsequent measurement of the spectral photoelectrochemical characteristics of electroconcentration products. It has been found that in solutions of 1M ammonium acetate containing Cu2+ ions, the cathodic polarization of TiO2-based photoelectrode leads to the appearance of a cathode photocurrent and the values of photocurrent quantum yield increase with increasing content of copper ions in the solution. The spectral sensitivity of the surface layer corresponds to the absorption spectrum of Cu2O. The sensitivity of stripping voltammetry method to copper Cu (II) using the materials studied was 0.3 mg•l-1. It is shown that the inversion photoelectrochemical method is promising in the selective determination of copper concentration in liquids.

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