Literature

So far, more than 260 peer reviewed papers have been published on the application of DryLab – a complete list of which you can find here.

DryLab draws on the philosophy described in the three most famous Solvophobic Theory papers IIIIII of Csaba Horváth, which were developed in the years 1975-1977 at Yale University (see also literature by Dr. Imre Molnár).

Read more about the Fundamentals of DryLab and its History.

Keyword Year

Tuning selectivity in cation-exchange chromatography applied for monoclonal antibody separations, part 1: Alternative mobile phases and fine tuning of the separation

E. Farsang et. al
J Pharm Biomed Anal., 168, 10 May, 138-147 (2019)

Keywords: Cation-exchange chromatography, pH gradient, Salt gradient, Salt-mediated pH gradient, Monoclonal antibody, Method development

PDF
http://doi.org/10.1016/j.jpba.2019.02.024

Highlights:

  • Alternative buffer systems are suggested for CEX separation of mAbs.
  • Benefits of salt mediated pH gradient are discussed.
  • The combination of a “true” pH- and salt gradients extends the possibilities of method development.
  • Retention modeling and method optimization were performed by DryLab®4
  • Complete method development is feasible within 6 h.

 


Is hydrophobic interaction chromatography the most suitable technique to characterize site-specific antibody-drug conjugates?

V. D’Atri, R. Pell, A. Clarke, D. Guillarme, Sz. Fekete
J. Chromatogr. A, 1586, 8 February, 149-153 (2019)

Keywords: Site-specific antibody drug conjugates, Hydrophobic interaction chromatography, Reversed phase liquid chromatography, Mass spectrometry, Biopharmaceuticals

PDF
http://doi.org/10.1016/j.chroma.2018.12.020

Highlights:

  • ADC consists of a recombinant mAb covalently linked to a cytotoxic molecule.
  • Hydrophobic interaction chromatography represents the gold standard for ADC analysis.
  • New site-specific ADC formats are more homogeneous than their previous generations.
  • RPLC is proposed as alternative method to HIC for site-specific ADC characterization.
  • Retention and resolution modeling was performed with DryLab®4 software.

 


Computer-assisted UHPLC–MS method development and optimization for the determination of 24 antineoplastic drugs used in hospital pharmacy

N. Guichard, Sz. Fekete, D. Guillarme, P. Bonnabry, S. Fleury-Souverain
J Pharm Biomed Anal., 164, 5 February, 395-401 (2019)

Keywords: Retention modeling, Antineoplastic agent, Drylab, Method development, Reversed phase liquid chromatography

PDF
http://doi.org/10.1016/j.jpba.2018.11.014

This study reports the use of retention modeling software for the successful method development of 24 injectable antineoplastic agents. Firstly, a generic screening of several stationary and mobile phases (using various organic modifiers and pH) was achieved. Then, an optimization procedure of mobile phase temperature, gradient profile and mobile phase binary composition was conducted through only 28 real experiments using retention modeling software for data treatment. Finally, the optimized separation was achieved with a mobile phase consisting in 10 mM acetic acid at pH 5.1 (A) and acetonitrile (B). A Waters CORTECS® T3 column (100 × 2.1 mm, 1.6 μm) operated at 25 °C with a gradient time of 17.5 min (0-51%B) at a flow rate of 0.4 mL/min was used. The prediction offered by the retention model was found to be highly reliable, with an average error lower than 1%. A robustness testing step was also assessed from a virtual experimental design. Success rate and regression coefficient were evaluated without the need to perform any real experiment. The developed LC-MS method was successfully applied to the analysis of pharmaceutical formulations and wiping samples from working environment.


Critical review of reports on impurity and degradation product profiling in the last decade

Sándor Görög
Trends Anal. Chem., 101, April 2018, 2-16 (2018)

Keywords: Impurity, Degradant, Chromatography, Spectroscopy, Hyphenated methods, Enantiomer

PDF
http://doi.org/10.1016/j.trac.2017.09.012

Drug impurity and degradation profiling mean the detection, structure elucidation and quantitative determination of impurities and degradation products in bulk drug materials and pharmaceutical formulations. This is today one of the most important fields of activities in pharmaceutical analysis. The reason for this is that unidentified, potentially toxicimpurities are health hazards, and in order to increase the safety of drug therapy, impurities should be identified and determined by selective methods.

The aim of this review is to characterise the state-of-art in the field of impurity and degradation profiling of drugs based on papers published in the last decade. The separation and determination of impurities and degradants with a known structure are discussed, but emphasis is placed on the structure elucidation and determination of new (unknown) impurities and degradation products by off-line and on-line chromatographic-spectroscopic methods. The analytical aspects of enantiomeric purity of chiral drugs are also discussed.


Implementation of a generic liquid chromatographic method development workflow: Application to the analysis of phytocannabinoids and Cannabis sativa extracts

Sz. Fekete et. al
J Pharm Biomed Anal., 155, 5 June 2018, 116-124 (2018)

Keywords: Cannabinoids, Cannabis, Method development, Robustness test, DryLab, UHPLC

PDF
http://doi.org/10.1016/j.jpba.2018.03.059

A generic liquid chromatographic method development workflow was developed and successfully applied to the analysis of phytocannabinoids and Cannabis sativaextracts. Our method development procedure consists in four steps:

i)The screening of primary parameters (i.e. stationary phase nature, organic modifier nature and approximate mobile phase pH) was carried out with a generic gradient on a short narrow bore column, using a system able to accommodate numerous solvents/buffers and columns. Instead of complete peak tracking, the number of peaks which can be separated was considered as a response at this level, to save time.

ii)The optimization of secondary parameters (i.e. gradient conditions, mobile phase temperature and pH within a narrow range) requires only 12 initial experiments and the use of HPLC modeling software for data treatment. It allows to find out the best retention and selectivity for the selected compounds. Peak tracking was performed with a single quadruple mass detector in single ion recording mode, and UV detection (in a broad wavelength range).

iii)The refinement step allows to further adjust column efficiency, by tuning column length and mobile phase flow rate. This can also be done virtually using HPLC modeling software.

iv)The robustness testing step was also evaluated from a virtual experimental design. Success rate and regression coefficients were estimated in about 1 min, without the need to perform any real experiment.

At the end, this method development workflow was performed in less than 4 days and minimizes the costs of the method development in liquid chromatography.


Optimization of Thin-layer Chromatography and High-Performance Liquid Chromatographic Method for Piper guineense Extracts

Eunice Ego Mgbeahuruike, Heikki Vuorela, Teijo Yrjönen, Yvonne Holm
Nat. Prod. Commun., 13, No. 1, 25-28 (2018)

Keywords: DryLab Simulation, Mobile-phase composition, TLC, HPLC, Piperine

PDF
http://doi.org/10.1177/1934578X1801300109

In this study, a thin-layer chromatography (TLC) and a high performance liquid chromatographic (HPLC) methods were developed for the chemical profiling, qualitative and quantitative analysis of P. guineense extracts. To obtain a chromatogram with satisfactory resolution and favorable retention time, DryLab software was used to simulate and optimize a HPLC method for the analysis of P. guineense extracts. The aim was to achieve the best possible overall resolution while keeping the analysis time and solvent consumption to a minimum. With the optimized method, a total of 16 main components in the extract were separated with favorable resolution. Optimal TLC conditions were also developed using solvents of various solvent strength (ST) and solvent selectivity (PS) values. The mobile phase composition was systematically tested using various proportions of solvents differing in ST and PS values under the same experimental conditions. During the optimization, emphasis was set on achieving the best possible overall separation of the main components of the extracts (for example piperine). In addition, the effects of the developing chamber was tested using three types of unsaturated chamber conditions: horizontal chamber in sandwich configuration, horizontal chamber in non-sandwich configuration and twin-trough vertical chamber. During the study, a TLC method was developed, and the best mobile-phase composition giving favorable resolution of the bands was toluene: ethyl acetate (PS 6-4 corresponding to 60:40 % v/v). The developing chamber conditions did not affect the TLC separation efficacy in the analysis of P. guineense extracts. The HPLC method was applied to determine the percentage content of piperine in P. guineense. The piperine content was 0.43 % w/w, linearity (0.997), interday precision (% relative standard deviation (RSD), 1.6), intraday precision (% RSD, 2.7 – 5.9), recovery (98.4%), limit of detection (0.001 μg /mL) and limit of quantification (0.003 μg /mL).

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