Anion-switchable supramolecular gels for controlling pharmaceutical crystal growth

Jonathan A. Foster, Marc-Oliver M. Piepenbrock, Gareth O. Lloyd, Nigel Clarke, Judith A. K. Howard, Jonathan W. Steed

Research output: Contribution to journalArticle

226 Citations (Scopus)

Abstract

We describe the use of low-molecular-weight supramolecular gels as media for the growth of molecular crystals. Growth of a range of crystals of organic compounds, including pharmaceuticals, was achieved in bis(urea) gels. Low-molecular-weight supramolecular gelators allow access to an unlimited range of solvent systems, in contrast to conventional aqueous gels such as gelatin and agarose. A detailed study of carbamazepine crystal growth in four different bis(urea) gelators, including a metallogelator, is reported. The crystallization of a range of other drug substances, namely sparfloxacin, piroxicam, theophylline, caffeine, ibuprofen, acetaminophen (paracetamol), sulindac and indomethacin, was also achieved in supramolecular gel media without co-crystal formation. In many cases, crystals can be conveniently recovered from the gels by using supramolecular anion-triggered gel dissolution; however, crystals of substances that themselves bind to anions are dissolved by them. Overall, supramolecular gel-phase crystallization offers an extremely versatile new tool in pharmaceutical polymorph screening.

Original languageEnglish
Pages (from-to)1037-1043
Number of pages7
JournalNature Chemistry
Volume2
Issue number12
DOIs
Publication statusPublished - Dec 2010

Keywords

  • ORGANOGELS
  • DIFFUSION
  • FORM-I
  • MASS ORGANIC GELATORS
  • INTERFACE
  • CRYSTALLIZATION
  • CARBAMAZEPINE
  • POLYMORPHS
  • COMPONENT
  • DIVERSITY

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