title: Racemic species of sodium ibuprofen: characterization and polymorphic relationships.
abstract: Racemic and homochiral sodium ibuprofen were characterized by thermal analysis and powder X-ray diffractometry. The melting point phase diagram was constructed and thermodynamic calculation was performed. In contrast to racemic ibuprofen, which is a racemic compound, racemic sodium ibuprofen forms both a racemic conglomerate (termed the gamma-form) as well as two polymorphic racemic compounds, alpha and beta, which are less stable monotropes. From the supercooled liquid, alpha and beta crystallized along with the original gamma-form. Forms alpha and beta are "enantiotropically related" with a transition temperature between 75 degrees and 113 degrees C, but can be considered to be metastable monotropes of the racemic conglomerate, the stable gamma-form.
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Weaver-Densford Hall, 308 Harvard Street Southeast, Minneapolis, MN 55455-0343, USA.
authors.forename: Geoff G Z
authors.initials: GG
authors.lastname: Zhang
authors.forename: Sophia Y L
authors.initials: SY
authors.lastname: Paspal
authors.forename: Raj
authors.initials: R
authors.lastname: Suryanarayanan
authors.forename: David J W
authors.initials: DJ
authors.lastname: Grant
mesh_terms: D007052:Ibuprofen / Q000032:analysis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007052:Ibuprofen