Quantitative Analysis and Differential Evaluation of Radix Bupleuri Cultivated in Different Regions Based on HPLC-MS and GC-MS Combined with Multivariate Statistical Analysis
All articles published by are made immediately available worldwide under an open access license. No special permission is required to reuse all or part of the article published by , including figures and tables. For articles published under an open access Creative Common CC BY license, any part of the article may be reused without permission provided that the original article is clearly cited. For more information, please refer to https:///openaccess.
Feature papers represent the most advanced research with significant potential for high impact in the field. A Feature Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for future research directions and describes possible research applications.
Anticonvulsants In Migraine Prophylaxis: A Cochrane Review
Editor’s Choice articles are based on recommendations by the scientific editors of journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.
By Milena Rmandić 1 , Ana Stajić 2 , Jasna Jančić 3 , Janko Samardžić 3, 4 , Nebojša Jović 3, † and Anđelija Malenović 1, *
In this research, a UHPLC–MS/MS method was developed and validated for the determination of zonisamide in dried plasma spots (DPS) and dried blood spots (DBS). Detection of zonisamide and internal standard, 1-(2, 3-dichlorphenyl)piperazine, was carried out in ESI+ mode by monitoring two MRM transitions per analyte. Total run time, less than 2.5 min, was achieved using Acquity UPLC BEH Amide (2.1 × 100 mm, 1.7 µm particle size) column with mobile phase comprising acetonitrile–water (85:15%, v/v) with 0.075% formic acid. The flow rate was 0.225 mL/min, the column temperature was 30 °C and the injection volume was 3 µL. Desolvation temperature, desolvation gas flow rate, ion source temperature and cone gas flow rate were set by the IntelliStart software tool in combination with tuning. All of the Guthrie cards were scanned, and DPS/DBS areas were determined by the image processing tool. The influence of hematocrit values (20–60%) on accuracy and precision was evaluated to determine the range within which method for DBSs is free from Hct or dependency is within acceptable limits. The validated method was applied to the determination of zonisamide levels in DPS and DBS samples obtained from patients confirming its suitability for clinical application. Finally, the distribution of zonisamide into the red blood cells was estimated by correlating its DPS and DBS levels.
Medical & Dosing Calculator Builder
Zonisamide (1, 2-benzisoxazole-3-methanesulfonamide) is an antiepileptic drug (AED) chemically distinct from other AEDs, with a dual mechanism of action, and thus effective in patients whose seizures are resistant to other anticonvulsants. Its biotransformation products are neither active nor toxic since 20% of zonisamide undergoes acetylation to form N-acetyl zonisamide, and 50% is reduced to form the open ring metabolite 2-sulfamoylacetyl phenol (SMAP), which is eliminated as glucuronide, while 30% is excreted unchanged in the urine [1]. The drug is not highly bound to human plasma proteins, but its binding affinity for red blood cells (RBCs) is eight times higher than that for plasma proteins, and a marked concentration of zonisamide can be observed in human RBCs [2].
For the determination of zonisamide (ZNS) in plasma/serum HPLC [3, 4], LC-MS [5], LC-MS/MS [6, 7] and UHPLC–MS/MS [8] methods were reported, while in dried plasma spots (DPSs) it was quantified by HPLC-UV method [9]. The reported HPLC methods suffer from incorrect validation procedures and inadequate lower limit of quantification (LLOQ), while LC-MS methods encountered several disadvantages such as a lack of specificity due to the application of selected ion monitoring (SIM) rather than multiple reaction monitoring (MRM) modes [5], inadequate LLOQ [6], laborious sample preparation procedures [5, 7] or compromised cost-effectiveness due to long analytical run [7]. UHPLC–MS/MS dramatically improved analytical run times without sacrificing peak resolution, but its clinical application is limited only to serum after protein precipitation for sample pre-treatment [8].
Thus far, a method suitable for quantification of ZNS in both plasma and blood was not proposed, providing means to correlate obtained concentrations and apply findings in routine clinical practice. Therefore, the aim of this research was to develop the first UPLC–MS/MS method for the quantification of ZNS in DPSs and dried blood spots (DBSs) with the aid of image processing for precise estimation of DBS and DPS areas after scanning of the Guthrie card on which the appropriate matrix volume was spotted. For the appropriate collection of DBSs, regardless of hematocrit (Hct) value, we applied a previously verified procedure for consistent application of a blood sample volume and formation of spots of the uniform area [10].
Th Annual Meeting Of The Child Neurology Society
Furthermore, both methods were validated in accordance with Food and Drug Administration (FDA) [11], European Medicines Agency (EMA) [12] and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) M10 guidelines [13] on bioanalytical method validation, as well as European Bioanalysis Forum (EBF) recommendations on DBS assays [14]. The DBS-based method was validated using 5 Hct levels (20.2%, 30%, 42%, 50.2% and 60%) to determine the range within which the method is independent of Hct or dependency is within acceptable limits. Finally, the suitability of the developed methods for the clinical application was confirmed by analyzing samples obtained from epileptic children and youth.
Reference standard of ZNS, as well as the internal standard, 2, 3-dichlorphenilpiperazine was obtained from LGC standards (LGC Group, Teddington, UK) (Figure 1). Acetonitrile, methanol and water, all LC-MS grade, were purchased from Thermo Fischer Scientific (Massachusetts, USA). Formic acid (purity 99%), acetic acid, ammonium formate and ammonium acetate, also LC-MS grade, were obtained from Sigma Aldrich (Taufkirchen, Germany). Vacutainer K2EDTA tubes for blood collection were supplied by Becton Dickinson, UK.
Air displacement Eppendorf pipette with variable volume 1–5 mL (Eppendorf AG, Hamburg, Germany) was utilized during the preparation of blood samples of target Hct values. Whatman 903 cellulose-based Guthrie cards utilized for DBS and DPS sample collection were procured from GE Healthcare (Buckinghamshire, UK). Thermo automatic pipettes with fix volume of 50 µL, variable volume of 10–100 µL and 0.1–10 µL (Thermo Fischer Scientific, Massachusetts, USA) and non-commercial puncher were used during the sample deposition onto the blotting paper, as well as during analytical sample preparation procedure. Fisherbrand™ Zipper Seal Sample Bags (Fisher Scientific, Hampton, VA, USA) with Sorb-It 1 g desiccant packs (Clariant, Ahrensburg, Germany) were used for card storage. Millipore membrane filters of 0.22 µm pore size and 47 mm diameter were purchased from Sigma Aldrich (Merck KGaA, Darmstadt, Germany). Blank plasma was obtained from Sanquin (Amsterdam, The Netherlands), while blank blood was obtained from healthy volunteers. Plasma and blood samples were collected from patients of the Clinic of Neurology and Psychiatry for Children and Youth in Belgrade, Serbia, who are using ZNS in therapy.
Pdf) Lamotrigine Versus Levetiracetam Or Zonisamide For Focal Epilepsy And Valproate Versus Levetiracetam For Generalised And Unclassified Epilepsy: Two Sanad Ii Non Inferiority Rcts
The chromatographic analysis was performed on the Waters Acquity UPLC H-Class system. Appropriate chromatographic behavior of ZNS and IS for a total run time of less than 2.5 min was achieved using Acquity UPLC BEH Amide (2.1 × 100 mm, 1.7 µm particle size) column and isocratic elution. The mixture of acetonitrile and water (85:15%, v/v), with added formic acid to the final content of 0.075%, was selected as the optimal mobile phase composition. The flow rate was 0.225 mL min
The analysis was conducted on Waters Xevo TQD, a triple quadrupole mass spectrometer armed with an electrospray ion source (ESI). Detection and quantification of the ZNS and IS were carried out in the positive electrospray ionization (ESI+) followed by scanning in multiple reaction monitoring (MRM) mode. Two MRM transitions were used/monitored for each analyte. Waters Xevo TQD’s operating parameters such as desolvation temperature, desolvation gas flow rate, ion source temperature and cone gas flow rate were set at 500 °C, 1000 L h
, respectively, while the optimal value of collision energy (CE), cone voltage (CV) and capillary voltages for each m/z transition was set by IntelliStart software tool in combination with tuning. Characteristic m/z transitions (parent > product ion), as well as CE and CV for each transition, are listed in Table 1.
Lgs Foundation 2016 Conference
EBA 20 Hettich centrifuge (Hettich GmbH & Co. KG, Tuttlingen, Germany) and Mythic 18 hematology analyzer (Orphée Medical, Geneva, Switzerland) were utilized during the preparation of blood samples of target Hct levels. Vortex Genie 2 Digital (Scientific Industries, Inc., Bohemia, NY, USA) was employed during the sample preparation procedure. All DPS and DBS samples were scanned by HP Scanjet 4070 Photosmart Scanner (HP, Palo Alto, CA, USA).
Mass Lynx V4.1 software (Waters Corporation, Milford, MA, USA) provided the execution of all operations at the Waters Acquity UPLC/Xevo TQD systems. The IBM
Office Excel 2013 software packages (Microsoft Corporation, Redmond, Washington, DC, USA) were used to process the results and perform the necessary statistical tests. The image processing tool of Matlab R2018b software (MathWorks, Natick, MA, USA) was employed to determine the accurate plasma and blood spot area. The Greenness Analytical
0 comments
Post a Comment