Jump to main content
Jump to site search

Issue 42, 2016
Previous Article Next Article

Polymorphism of the antiviral agent clevudine

Author affiliations


Polymorphism of the antiviral drug clevudine is addressed here for the first time. Three polymorphs were isolated and investigated in order to establish their structural relationships as well as their aqueous solubilities and thermodynamic stabilities. Forms 1, 2 and 3 crystallize in the monoclinic space group P21 with 4, 2 and 8 molecules per unit cell respectively. Extensive H-bonding occurs in all three crystals, leading to stacked layers in Forms 1 and 3, while Form 2 contains close-packed columns of clevudine molecules. A combination of hot stage microscopy, differential scanning calorimetry, variable-temperature PXRD and the observation of solvent-mediated transformations, enabled assignment of relevant phase transitions as well as the construction of a schematic energy-temperature diagram, which reflects enantiotropic relationships, with Form 2 as the stable form below ∼175 °C. Possible implications of the results in the context of further development and expected widespread use of this antiviral are discussed.

Graphical abstract: Polymorphism of the antiviral agent clevudine

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Sep 2016, accepted on 26 Sep 2016 and first published on 27 Sep 2016

Article type: Paper
DOI: 10.1039/C6CE01975G
Citation: CrystEngComm, 2016,18, 8172-8181
  •   Request permissions

    Polymorphism of the antiviral agent clevudine

    T. J. Noonan, B. Mzondo, S. A. Bourne and M. R. Caira, CrystEngComm, 2016, 18, 8172
    DOI: 10.1039/C6CE01975G

Search articles by author