title: Propylene carbonate quantification by its derivative 3,5-diacetyl-1,4-dihydro-2,6-lutidine.
abstract: Propylene carbonate (PC) is a non-toxic solvent currently used in various pharmaceutical formulations. Consequently, a simple, cost-effective and most accurate analytical method for the quantification of this optical inert solvent is of major interest. Based on a consecutive three-step reaction 3,5-diacetyl-1,4-dihydro-2,6-lutidine was obtained from PC and used for quantification by either UV and fluorescent detection. Data were compared with results from LC-ESI-MS as a reference method. After using Mandel's test for linearity assessment of the calibration curves, linear fitting was used for LC-ESI-MS and spectrofluorimetry, while a polynomial 3rd order curve fitting was used for spectrophotometry. High intra- and inter-day precision as well as high accuracy were confirmed for all three analytical methods (spectrophotometry, spectrofluorimetry and LC-ESI-MS). The comparison of all three methods was assessed using correlation coefficients and Bland-Altman plots, both showing satisfying results with a high degree of agreement. The new method confirmed its applicability for PC quantification in two formulations, namely a PC-enriched cream and polyester microimplants. This new quantification method for PC is a reliable alternative to highly sophisticated chromatographic methods.
authors.affiliation: Department of Pharmaceutics, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany. Electronic address: daris.grizic@uni-bonn.de.
authors.forename: Daris
authors.initials: D
authors.lastname: Grizić
authors.affiliation: Pharmaceutical Chemistry I, Pharmaceutical Institute, University of Bonn, Brühler Str. 7, 53119 Bonn, Germany.
authors.forename: Pascal
authors.initials: P
authors.lastname: Heimer
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71 000 Sarajevo, Bosnia and Herzegovina.
authors.forename: Edina
authors.initials: E
authors.lastname: Vranić
authors.affiliation: Pharmaceutical Chemistry I, Pharmaceutical Institute, University of Bonn, Brühler Str. 7, 53119 Bonn, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Imhof
authors.affiliation: Department of Pharmaceutics, Pharmaceutical Institute, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany; FDE (EA4267), University of Dijon/Franche-Comté, 19 rue Ambroise Paré, 25030 Besançon Cedex, France. Electronic address: alf.lamprecht@uni-bonn.de.
authors.forename: Alf
authors.initials: A
authors.lastname: Lamprecht
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid; D003931:Diacetyl / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D008956:Models, Chemical; D015394:Molecular Structure; D011407:Propane / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry*; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D011725:Pyridines; C013093:2,6-lutidine; C045990:propylene carbonate; D003931:Diacetyl; D011407:Propane
keywords: Dihydropyridine condensation; LC-ESI-MS; Propylene carbonate; Residual solvent quantification