title: Crystal structures of tiotropium bromide and its monohydrate in view of combined solid-state nuclear magnetic resonance and gauge-including projector-augmented wave studies.
abstract: Tiotropium bromide is an anticholinergic bronchodilator used in the management of chronic obstructive pulmonary disease. The crystal structures of this compound and its monohydrate have been previously solved and published. However, in this paper, we showed that those structures contain some major errors. Our methodology based on combination of the solid-state nuclear magnetic resonance (NMR) spectroscopy and quantum mechanical gauge-including projector-augmented wave (GIPAW) calculations of NMR shielding constants enabled us to correct those errors and obtain reliable structures of the studied compounds. It has been proved that such approach can be used not only to perform the structural analysis of a drug substance and to identify its polymorphs, but also to verify and optimize already existing crystal structures.
authors.affiliation: Faculty of Pharmacy, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Warsaw, 02-093, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Pindelska
authors.affiliation: Faculty of Pharmacy, Medical University of Warsaw, Department of Physical Chemistry, Warsaw, 02-093, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Szeleszczuk
authors.affiliation: Faculty of Pharmacy, Medical University of Warsaw, Department of Physical Chemistry, Warsaw, 02-093, Poland.
authors.forename: Dariusz Maciej
authors.initials: DM
authors.lastname: Pisklak
authors.affiliation: Pharmaceutical Company Adamed Ltd., Czosnów, 05-152, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Majka
authors.affiliation: Faculty of Pharmacy, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Warsaw, 02-093, Poland.
authors.forename: Waclaw
authors.initials: W
authors.lastname: Kolodziejski
mesh_terms: D001993:Bronchodilator Agents / Q000737:chemistry; D018680:Cholinergic Antagonists / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D000069447:Tiotropium Bromide / Q000737:chemistry*
chemical_list: D001993:Bronchodilator Agents; D018680:Cholinergic Antagonists; D000069447:Tiotropium Bromide
keywords: GIPAW calculations; ab initio calculations; crystal structure; polymorphism; solid state NMR; solid state characterization; tiotropium bromide