Opening Pandora’s Box: Chirality, Polymorphism, and Stoichiometric Diversity in Flurbiprofen/Proline Cocrystals

Natalia Tumanova, Nikolay Tumanov, Koen Robeyns, Franziska Fischer, Luca Fusaro, Fabrice Morelle, Voraksmy Ban, Geoffroy Hautier, Yaroslav Filinchuk, Johan Wouters, Tom Leyssens, Franziska Emmerling

Research output: Contribution to journalArticle


Proline has been widely used for various cocrystallization applications, including pharmaceutical cocrystals. Combining enantiopure and racemic flurbiprofen and proline, we discovered 18 new crystal structures. Liquid-assisted grinding proved highly efficient to explore all the variety of crystal forms. A unique combination of state-of-the-art characterization techniques, comprising variable temperature in situ X-ray diffraction and in situ ball-milling, along with other physicochemical methods and density functional theory calculations, was indispensable for identifying all the phases. Analyzing the results of in situ ball-milling, we established a stepwise mechanism for the formation of several 1:1 cocrystals via an intermediate 2:1 phase. The nature of the solvent in liquid-assisted grinding was found to significantly affect the reaction rate and, in some cases, the reaction pathway.
Original languageEnglish
Pages (from-to)954-961
Number of pages8
JournalCrystal Growth & Design
Issue number2
Publication statusPublished - 4 Jan 2018


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