Application of retention modeling in chiral method development. I. Selection of isocratic composition for preparative separation with SFC

2021 ◽  
Vol 1651 ◽  
pp. 462308
Author(s):  
Abhijit Tarafder ◽  
Malik McKnight ◽  
Larry Miller
Keyword(s):  
Method Development ◽  
Preparative Separation ◽  
Selection Of

scholarly journals Analytical and preparative separation and isolation of functionalized fullerenes by conventional HPLC stationary phases: method development and column screening

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19211-19218
Author(s):  
Merve Ergun Dönmez ◽  
Helena Grennberg
Keyword(s):  
Method Development ◽  
Stationary Phases ◽  
Hplc Method ◽  
Complex Reaction ◽  
Preparative Separation ◽  
Isolation And Purification ◽  
Functionalized Fullerenes

Isolation and purification of functionalized fullerenes from often complex reaction mixtures is challenging. Here, a simple and efficient HPLC method is presented.

Using multiple platforms for critical reagents selection process to support pharmacokinetic ligand-binding assay development

Bioanalysis ◽  
2021 ◽  
Author(s):  
Elisa Oquendo ◽  
Xu Lin ◽  
Sally Ye ◽  
Kelly Coble ◽  
Christine Grimaldi
Keyword(s):  
Ligand Binding ◽  
Partial Correlation ◽  
Method Development ◽  
Binding Assay ◽  
Selection Process ◽  
Assay Development ◽  
Ligand Binding Assay ◽  
Biolayer Interferometry ◽  
Pharmacokinetic Assay ◽  
Selection Of

We have evaluated the utility of epitope binning on biolayer interferometry (BLI) as a strategy to funnel the selection of candidate pairs suitable for pharmacokinetic assay development. Totally, 8 anti-Ids in 64 possible combinations were tested by BLI, ELISA and Gyrolab®. Two epitope binning approaches were utilized, in-tandem and classic sandwich. Both formats identified four mutually exclusive bins providing 31 and 25 possible antibody pair combinations, respectively. In contrast, the ELISA and Gyrolab yielded 18 and 9 positive pairs, respectively, with only a partial correlation to the BLI results. Several positive pairs by ELISA and Gyrolab, screened negative by BLI. Just over half of the pairs predicted by BLI were positive on ELISA and less than a quarter were positive on Gyrolab. This evaluation showed, in our case, that BLI was limited in its ability to predict candidate pairs that would be successful in pharmacokinetic method development.

Forecasting the number of publication based on Web of Science and Scopus data integral index

2018 ◽  
pp. 60-83 ◽  
Author(s):  
Irina Mosicheva ◽  
Svetlana Parfenova ◽  
Vladislava Dolgova ◽  
Karina Bezrodnova ◽  
Elena Lyagushkina ◽  
...  
Keyword(s):  
Method Development ◽  
Web Of Science ◽  
National Policy ◽  
Digital Object Identifier ◽  
Integral Index ◽  
Russian Science ◽  
Technology Project ◽  
Global Science ◽  
Science And Technology Project ◽  
Selection Of

The study is completed within the framework of the state order of the Minstryof Education and Science of the Russian Federation “Monitoring and analysis of publication and patent activities in Russian and global science to support the national policy in science and technology” (Project No. 28.12616.2018/12.1). The authors aim at building relevant instruments for assessing and forecasting the total amount of Russian science publication based on the data of two global science citation systems, i. e. Web of Science and Scopus, with de-duplicating by digital object identifier used in both systems. The related tasks are defined: selection of the method to forecast the number of Web of Science indexed articles within the “back forecast” method; development of integral index to calculate the number of publication based on Web of Science and Scopus data; calculation and forecast of the number of articles and publications by G7 and BRICS states up to the year 2021 with scientometric methods based on Web of Science and Scopus data. The authors suggest a conceptually new method to calculate the integral index of publications based on Web of Science and Scopus data to exclude duplication. The total number of academic articles and publications (based on Web of Science and Scopus data) is calculated for the period 2007-2016, and the forecast is provided up to the year 2021.

scholarly journals Methodical approaches to bioassay of substances containing unstable functional groups

2018 ◽  
Vol 4 (1) ◽  
pp. 33-42
Author(s):  
Alexander L. Khokhlov ◽  
Ilya I. Yaichkov ◽  
Yuriy A. Dzhurko ◽  
Leonid N. Shitov ◽  
Anastasia A. Shitova
Keyword(s):  
Functional Groups ◽  
Mycophenolic Acid ◽  
Method Development ◽  
Biological Fluid ◽  
Volume Ratio ◽  
Storage Conditions ◽  
Phenolic Hydroxyl ◽  
Short Term ◽  
Selection Of

Introduction: This article describes the method development approaches for bioassay of substances containing unstable functional groups and forming unstable metabolites using the example of mycophenolic acid, methyldopa and mebeverine metabolites. Materials and Methods: The concentration of mycophenolic acid, which contains one phenolic hydroxyl and forms glucuronides during metabolism, was measured in plasma using HPLC-MS/MS, HPLC-MS and GC-MS. The determination of methyldopa, containing two phenolic hydroxyls, in stabilised plasma was performed by HPLC-MS/MS in the range of 0.02-3.00 μg/ml. Desmethyl mebeverine acid, which contains one phenolic hydroxyl and is metabolised by forming phenolic glucuronide, was assayed simultaneously with mebeverine acid in the range of 10-2000 ng/ml. Results and Discussion: The selection of storage conditions of the samples containing unstable substances should begin with selecting an anticoagulant based on the study of its short-term stability and freeze/thaw stability. If an unacceptable result is obtained, a combination of the anticoagulant and a stabiliser solution, as well as a concentration of this solution and its volume ratio to the biological fluid should be titrated. After which, this method should be validated by using the selected anticoagulant or the combination of the anticoagulant and stabiliser solution. Conclusion: The application of this approach to developing a bioanalytical method for determination of unstable compounds makes it possible to avoid obtaining false assay results.

scholarly journals A review on analytical method development, optimization and validation of combination of Azithromycin and benzoyl peroxide by RP-HPLC using design of experiment as per ICH guideline

2018 ◽  
Vol 6 (02) ◽  
pp. 53-63
Author(s):  
Narendra Singh ◽  
Yogendra Singh ◽  
R. S. Bhadauria ◽  
Jeyabalan Govindasamy
Keyword(s):  
Analytical Method ◽  
Mobile Phase ◽  
Method Development ◽  
Degradation Products ◽  
High Specificity ◽  
Cost Effective ◽  
Review Literature ◽  
Phase Selection ◽  
Drug Products ◽  
Selection Of

Pharmaceutical analysis is one of the most challenging fields of analytical chemistry. Pharmaceutical analysts carry out the qualitative and quantitative control of APIs and drug products and also develop and validate appropriate methods. One of my main goals was to develop modern, rapid, precise and reproducible, but also cost-effective HPLC assay methods which are generally available and applicable for most users. The aim of this work was to develop LC methods for both compounds. The assay of erythromycin by LC offers several advantages, such as high specificity, the possibility of determining and quantifying impurities and degradation products, and improved accuracy. The developed methods were validated. My whole work containing following plan of work as Selection of drug, Review Literature, FITR of both drugs and Mixture, Preparation of standard solutions, Preparation of sample of pure drug in Standard solution, Method development by HPLC (as Selection of solvents to be used as diluents and mobile phase, Selection of wavelength, Selection of mobile phase and Selection of chromatographic conditions) Preparation of Mobile phase, Preparation of standard calibration curve combination of drug, Optimization of HPLC condition using box behnken design. Validation of analytical method following parameters as per ICH guidelines. (i). System suitability (ii). Linearity and range (iii). Specificity (iv).Accuracy and precision (v). Limits of detection (LOD) and Quantitation (LOQ). (vi). Selectivity and (vii).Robustness.

scholarly journals Toward a Quality Guide to Facilitate the Transference of Analytical Methods from Research to Testing Laboratories: A Case Study

2009 ◽  
Vol 92 (6) ◽  
pp. 1821-1832 ◽  
Author(s):  
Krisnha Bisetty ◽  
Njabulo Joyfull Gumede ◽  
Laura Escuder-Gilabert ◽  
Salvador Sagrado
Keyword(s):  
Research Laboratory ◽  
Method Development ◽  
A Priori ◽  
Differential Pulse ◽  
Internal Quality ◽  
Concrete Case ◽  
Testing Laboratories ◽  
Selection Of

Abstract At present, there is no single viewpoint that defines QA strategies in analytical chemistry. On the other hand, there are no unique protocols defining a set of analytical tasks and decision criteria to be performed during the method development phase (e.g., by a single research laboratory) in order to facilitate the transference to the testing laboratories intending to adapt, validate, and routinely use this method. This study proposes general criteria, a priori valid for any developed method, recommended as a provisional quality guide containing the minimum internal tasks necessary to publish new analytical method results. As an application, the selection of some basic internal quality tasks and the corresponding accepted criteria are adapted to a concrete case study: indirect differential pulse polarographic determination of nitrate in water samples according to European Commission requisites. Extra tasks to be performed by testing laboratories are also outlined.

scholarly journals OpenMx: A Modular Research Environment for Item Response Theory Method Development

2020 ◽  
Vol 44 (7-8) ◽  
pp. 561-562
Author(s):  
Joshua N. Pritikin ◽  
Carl F. Falk
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Method Development ◽  
Source Code ◽  
Theory Method ◽  
Response Theory ◽  
Research Environment ◽  
Software Packages ◽  
Public Repositories ◽  
Selection Of

There are many item response theory software packages designed for users. Here, the authors introduce an environment tailored to method development and simulation. Implementations of a selection of classic algorithms are available as well as some recently developed methods. Source code is developed in public repositories on GitHub; your collaboration is welcome.

scholarly journals Structure Driven Prediction of Chromatographic Retention Times: Applications to Pharmaceutical Analysis

2021 ◽  
Vol 22 (8) ◽  
pp. 3848
Author(s):  
Roman Szucs ◽  
Roland Brown ◽  
Claudio Brunelli ◽  
James C. Heaton ◽  
Jasna Hradski
Keyword(s):  
Pharmaceutical Analysis ◽  
Method Development ◽  
Model Building ◽  
Degradation Products ◽  
Reversed Phase ◽  
Chromatographic Retention ◽  
Retention Models ◽  
Optimal Separation ◽  
Main Component ◽  
Selection Of

Pharmaceutical drug development relies heavily on the use of Reversed-Phase Liquid Chromatography methods. These methods are used to characterize active pharmaceutical ingredients and drug products by separating the main component from related substances such as process related impurities or main component degradation products. The results presented here indicate that retention models based on Quantitative Structure Retention Relationships can be used for de-risking methods used in pharmaceutical analysis and the identification of optimal separation conditions for separation of known sample constituents with postulated/hypothetical components. The prediction of retention times for hypothetical components in established methods is highly valuable as these compounds are not usually readily available for analysis. Here we discuss the development and optimization of retention models, selection of the most relevant structural molecular descriptors, regression model building and validation. We also present a practical example applied to chromatographic method development and discuss the accuracy of these models on selection of optimal separation parameters.

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