1. Determination of topiramate in human plasma using liquid chromatography tandem mass spectrometryTanja Vnučec, Lea Cvitkovič-Maričič, Helena Prosen, Darinka Brodnjak-Vončina, 2013, original scientific article Abstract: The LC-MS/MS method for determination of the anti-epileptic drug topiramate (TPM) in human plasma was developed and validated for pharmacokinetic and bioequivalence study purposes. For quantitative determination of TPM values the method with deuterated internal standard (topiramate-d12) and liquid chromatography with tandem mass spectrometry was used. TPM was extracted from the human plasma using the solid-phase extraction procedure on a Strata X extraction column. Negative ions were monitored in the selected reaction monitoring mode (SRM) and transitions m/z 338.2 > 78.2 and m/z 350.3 > 78.2 were used for the quantitative evaluation of TPM and the internal standard, respectively. The results obtained from validation were statistically evaluated according to the requirements of European Medicines Agency (EMA) and Food and Drug Administration (FDA) regulatory guidelines. The linearity of the method was checked within a concentration range from 10 to 2000 ng/mL. Successful validation confirmed that this method is precise, accurate, sensitive and therefore suitable for determination of topiramate plasma levels in pharmacokinetic and bioequivalence studies.
Keywords: topiramate, liquid chromatography tandem mass spectroscopy, human plasma, bioequivalence study
Published in DKUM: 18.08.2017; Views: 1206; Downloads: 91
 Full text (189,19 KB)
This document has many files! More... |
2. Determination of candesartan in human plasma with liquid chromatography - tandem mass spectrometryVanja Forjan, Lea Cvitkovič-Maričič, Helena Prosen, Darinka Brodnjak-Vončina, 2016, original scientific article Abstract: A sensitive, specific and rapid liquid chromatography - tandem mass spectrometry method was developed and validated for the determination of candesartan in human plasma. Analyte was separated from endogenous components present in plasma by solid phase extraction. Chromatographic separation was performed on Gemini C18 analytical column using mobile phase acetonitrile – 5 mM ammonium formate pH 2 (90:10, v/v) at flow rate of 0.3 mL/min. For detection, tandem mass spectrometry in SRM mode with positive electrospray ionization was used. The mass transitions m/z 441.1 > 263.1 and 445.1 > 267.1 were used to determine candesartan by using candesartan-d4 as an internal standard. After development, the method was validated according to the requirements of EMA regulatory guidelines in the concentration range 1 - 400 ng/ml in human plasma. Limit of quantification (LLOQ) was 1 ng/ml. The developed and validated method proved to be very fast and reproducible and was therefore successfully implemented in pharmacokinetic and bioequivalence studies with large number of study samples.
Keywords: candesartan, liquid chromatography, tandem mass spectrometry, human plasma
Published in DKUM: 17.08.2017; Views: 1167; Downloads: 359
Full text (215,54 KB)
This document has many files! More... |
3. |
4. Chiral discrimination in mobile phases for HPLCRenato Lukač, Andrew J. Clark, Syma Khalid, Alison Rodger, Alan Snedden, P. Mark Rodger, 2002, original scientific article Abstract: In this paper we present an algorithm and some preliminary results of a computer simulation study designed to elucidate the molecular interaction mechanisms associated with chiral discrimination in chiral high performance liquid chromatography (HPLC). Molecular dynamics simulations have been performed on a novel active stationary phase constituent based on disaccharides and a model analyte in a typical solvent used as mobile phase in chiral HPLC. The results are interpreted in terms of typical binding geometries and energies found from the simulations. This paper provides basic algorithms for predicting enantiometric selectivity and for investigating the implications for choice of parameters such as solvent polarity and temperature for optimising chiral HPLC separations
Keywords: physical chemistry, liquid crystals, liquid chromatography, computer simulations, spectroscopy
Published in DKUM: 07.06.2012; Views: 1718; Downloads: 53
 Link to full text |
