title: Structural study of piracetam polymorphs and cocrystals: crystallography redetermination and quantum mechanics calculations.
abstract: Pharmaceutical compounds are mostly developed as solid dosage forms containing a single-crystal form. It means that the selection of a particular crystal state for a given molecule is an important step for further clinical outlooks. In this context, piracetam, a pharmaceutical molecule known since the sixties for its nootropic properties, is considered in the present work. This molecule is analyzed using several experimental and theoretical approaches. First, the conformational space of the molecule has been systematically explored by performing a quantum mechanics scan of the two most relevant dihedral angles of the lateral chain. The predicted stable conformations have been compared to all the reported experimental geometries retrieved from the Cambridge Structural Database (CSD) covering polymorphs and cocrystals structures. In parallel, different batches of powders have been recrystallized. Under specific conditions, single crystals of polymorph (III) of piracetam have been obtained, an outcome confirmed by crystallographic analysis.
authors.affiliation: UCPTS, Faculté des Sciences, Rue de Bruxelles 61, Namur B-5000, Belgium.
authors.forename: Anaëlle
authors.initials: A
authors.lastname: Tilborg
authors.forename: Denis
authors.initials: D
authors.lastname: Jacquemin
authors.forename: Bernadette
authors.initials: B
authors.lastname: Norberg
authors.forename: Eric
authors.initials: E
authors.lastname: Perpète
authors.forename: Catherine
authors.initials: C
authors.lastname: Michaux
authors.forename: Johan
authors.initials: J
authors.lastname: Wouters
mesh_terms: D018360:Crystallography, X-Ray; D016208:Databases, Factual; D015394:Molecular Structure; D018696:Neuroprotective Agents / Q000737:chemistry*; D010889:Piracetam / Q000737:chemistry*; D033362:Powder Diffraction; D011789:Quantum Theory
chemical_list: D018696:Neuroprotective Agents; D010889:Piracetam