title: Analysis of the polymorph changes of a drug candidate.
abstract: The effects of solvents, temperature and humidity on the stability of a former drug candidate obtained from Sanofi (Hungary) were examined by a slurry equilibration method, variable temperature and humidity X-ray powder diffractometry (VT/VH-XRPD) and differential scanning calorimetry (DSC). The VH-XRPD study showed that all 8 polymorphic forms of this material were stable in the interval 20-80 RH%. The VT-XRPD measurements indicated that all the polymorphs except Form II underwent changes in the range 30-200°C. The stable form was Form II, though Form IVb had almost the same stability. The investigation demonstrated that VT-XRPD is a very useful in situ method for relative stability studies.
authors.affiliation: Department of Pharmaceutical Technology, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary. Electronic address: lang@pharm.u-szeged.hu.
authors.forename: P
authors.initials: P
authors.lastname: Láng
authors.affiliation: Department of Physical Quality, Sanofi Pharmaceutical Company, Tó u. 1-5, H-1045 Budapest, Hungary.
authors.forename: E
authors.initials: E
authors.lastname: Várkonyi
authors.affiliation: Department of Thermal Process Technology, Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Ulrich
authors.affiliation: Department of Pharmaceutical Technology, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary.
authors.forename: P
authors.initials: P
authors.lastname: Szabó-Révész
authors.affiliation: Department of Pharmaceutical Technology, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Aigner
mesh_terms: D002152:Calorimetry, Differential Scanning; D004355:Drug Stability; D013535:Suspensions; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D013535:Suspensions
keywords: DSC; Polymorphs; Relative stability; Thermodynamic stability; VT/VH-XRPD