title: Solid-state NMR studies of form I of atorvastatin calcium.
abstract: Solid-state (13)C, (19)F, and (15)N magic angle spinning NMR studies of Form I of atorvastatin calcium are reported, including chemical shift tensors of all resolvable carbon sites and fluorine sites. The complete (13)C and (19)F chemical shift assignments are given based on an extensive analysis of (13)C-(1)H HETCOR and (13)C-(19)F HETCOR results. The solid-state NMR data indicate that the asymmetric unit of this material contains two atorvastatin molecules. A possible structure of Form I of atorvastatin calcium (ATC-I), derived from solid-state NMR data and density functional theory calculations of various structures, is proposed for this important active pharmaceutical ingredient (API).
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, China.
authors.forename: Wei David
authors.initials: WD
authors.lastname: Wang
authors.forename: Xudong
authors.initials: X
authors.lastname: Gao
authors.forename: Mark
authors.initials: M
authors.lastname: Strohmeier
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Shi
authors.initials: S
authors.lastname: Bai
authors.forename: Cecil
authors.initials: C
authors.lastname: Dybowski
mesh_terms: D000069059:Atorvastatin; D002247:Carbon Isotopes / Q000737:chemistry; D005461:Fluorine / Q000737:chemistry; D006538:Heptanoic Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D006538:Heptanoic Acids; D011758:Pyrroles; D005461:Fluorine; D000069059:Atorvastatin