Reference : Collaborative study of an liquid chromatographic method for the determination of R-timol...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Chemistry
Human health sciences : Pharmacy, pharmacology & toxicology
http://hdl.handle.net/2268/7470
Collaborative study of an liquid chromatographic method for the determination of R-timolol and other related substances in S-timolol maleate
English
Marini Djang'Eing'A, Roland mailto [Université de Liège - ULg > Département de pharmacie > Chimie analytique >]
Matthijs, N. [> > > >]
Heyden, Y. V. [> > > >]
Smeyers-Verbeke, J. [> > > >]
Dehouck, P. [> > > >]
Hoogmartens, J. [> > > >]
Silvestre, P. [> > > >]
Ceccato, Attilio mailto [Université de Liège - ULg > Département de pharmacie > Analyse des médicaments >]
Goedert, P. [> > > >]
Saevels, J. [> > > >]
Herbots, C. [> > > >]
Caliaro, G. [> > > >]
Herraez-Hernandez, R. [> > > >]
Verdu-Andres, J. [> > > >]
Campins-falco, P. [> > > >]
de Wauw, W. V. [> > > >]
De Beer, J. [> > > >]
Boulanger, Bruno [Université de Liège - ULg > Département de pharmacie > Analyse des médicaments >]
Chiap, Patrice mailto [Université de Liège - ULg > Département de pharmacie > Département de pharmacie >]
Crommen, Jacques mailto [Université de Liège - ULg > Département de pharmacie > Analyse des médicaments >]
Hubert, Philippe mailto [Université de Liège - ULg > Département de pharmacie > Chimie analytique >]
2005
Analytica Chimica Acta
Elsevier
546
2
182-192
Yes (verified by ORBi)
International
0003-2670
1873-4324
Amsterdam
The Netherlands
[en] collaborative study ; uncertainty estimation ; reproducibility ; R-timolol ; degradation products ; liquid chromatography
[en] A collaborative study applying an enantiomeric liquid chromatographic (LC) method was carried out to determine the content of the enantiomeric impurity R-timolol and other related substances in three different S-timolol maleate samples. Eight laboratories, all located in Europe, participated in the study. The quantitative results obtained were used to estimate the uncertainty on the content of the different impurities. For that purpose, a set-up was adapted from the ISO guidelines 5725-2, which allowed the estimation of the different variances, i.e. the between-laboratories (s(laboratories)(2)), the between-days (s(days)(2)) and the between-replicates (s(replicates)(2)), The variances of repeatability (s(r)(2)) and reproducibility (s(R)(2)) were then calculated using the equations s(r)(2) = s(replicates)(2) and s(R)(2) = s(replicates)(2) + s(days)(2) + s(laboratories)(2). For the timolol impurities, it was found that the estimated uncertainty seem to be concentration-dependent. Since the LC method which combines the compendial ones for enantiomeric purity and related substances testing was applied to evaluate uncertainty in this collaborative study, it was shown how a laboratory can evaluate the uncertainty of its results when applying the method in the future. (c) 2005 Elsevier B.V. All rights reserved.
Researchers ; Professionals ; Students
http://hdl.handle.net/2268/7470

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