RSC Publishing


Publishing

 

Cover image for New Journal of Chemistry, select for current issue

New Journal of Chemistry

New Journal of Chemistry.... the home of new and emerging multidisciplinary work in the chemical sciences.



Subscribers

  • PDF
  • HTML article

Non-subscribers

Free access



Paper

New J. Chem., 2007, 31, 1429 - 1436, DOI: 10.1039/b706677p

The third evolution of ionic liquids: active pharmaceutical ingredients

Whitney L. Hough, Marcin Smiglak, Héctor Rodríguez, Richard P. Swatloski, Scott K. Spear, Daniel T. Daly, Juliusz Pernak, Judith E. Grisel, Richard D. Carliss, Morgan D. Soutullo, James H. Davis, Jr.,Robin D. Rogers

A modular, ionic liquid (IL)-based strategy allows compartmentalized molecular level design of a wide range of new materials with tunable biological, as well as the well known physical and chemical, properties of ILs, which thus deserve consideration as tunable active pharmaceutical ingredients (APIs) with novel performance enhancement and delivery options. IL strategies can take advantage of the dual nature (discrete ions) of ILs to realize enhancements which may include controlled solubility (e.g., both hydrophilic and hydrophobic ILs are possible), bioavailability or bioactivity, stability, elimination of polymorphism, new delivery options (e.g., slow release or the IL-API as solvent), or even customized pharmaceutical cocktails. Here we exemplify this approach with, among others, lidocaine docusate (LD), a hydrophobic room temperature IL which, when compared to lidocaine hydrochloride, exhibits modified solubility, increased thermal stability, and a significant enhancement in the efficacy of topical analgesia in two different models of mouse antinociception. Studies of the suppression of nerve growth factor mediated neuronal differentiation in rat pheochromocytoma (PC12) cells suggests potential differences between LD and lidocaine hydrochloride at the cellular level indicating an entirely different mechanism of action. Taken together these results suggest that the unique physiochemical properties of ILs in general, may confer a novel effect for the bioactivity of an API due to (at least) slow-release properties in addition to novel delivery mechanisms.

Graphical abstract image for this article (ID: b706677p)