Selective Growth of a Stable Drug Polymorph by Suppressing the Nucleation of Corresponding Metastable Polymorphs

To stick or not to stick? Metastable (α) and stable (γ) polymorphs of indomethacin crystallize concomitantly from ethanol solutions. Crystallization in glass vials functionalized with perfluoroalkyl-terminated silane monolayers, however, leads to the exclusive growth of the stable polymorph. These monolayers create surfaces that inhibit the heterogeneous nucleation of α polymorph and thereby promote the growth of γ polymorph.