title: The methanol disolvate and the dihydrate of fexofenadine, an antihistamine drug.
abstract: Fexofenadine [systematic name: (+/-)-(4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)piperidinium-1-yl]-butyl]phenyl)-2-methylpropionate], crystallizes in two forms, viz. as the methanol disolvate, C32H39NO4.2CH4O, and as the dihydrate, C32H39NO4.2H2O. It exists in the two structures as a zwitterion, which self-assembles as dimers sustained by a pair of charged-assisted N-H...OOC hydrogen bonds. In the methanol disolvate, the supramolecular organization consists of discrete fexofenadine dimers solvated by four molecules of methanol. The dihydrate structure is sustained by a more extended hydrogen-bonding scheme, wherein the hydrated dimeric entities are interlinked by additional hydrogen bonds. The fexofenadine molecule adopts different and differently disordered conformations of the 1-hydroxybutyl residue in the two structures.
authors.affiliation: School of Chemistry, Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv, 69978 Tel-Aviv, Israel.
authors.forename: Limor
authors.initials: L
authors.lastname: Tessler
authors.forename: Israel
authors.initials: I
authors.lastname: Goldberg
mesh_terms: D018360:Crystallography, X-Ray; D039563:Histamine H1 Antagonists, Non-Sedating / Q000737:chemistry*; D006860:Hydrogen Bonding; D000432:Methanol; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D012995:Solubility; D016593:Terfenadine / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D039563:Histamine H1 Antagonists, Non-Sedating; D016593:Terfenadine; C093230:fexofenadine; D000432:Methanol