title: The Slow Molecular Mobility in Amorphous Ketoprofen and Ibuprofen.
abstract: The slow molecular dynamics in two active pharmaceutical drugs, ketoprofen and ibuprofen, have been studied by differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC). This study allowed finding the main kinetic features of the fast secondary (γ) relaxation, of the Johari-Goldstein relaxation, and of the main (glass transition) relaxation, in particular their distribution of relaxation times. The fragility index of the two glass formers was determined based on data from DSC and from TSDC. The obtained results were compared with those obtained by other experimental techniques, namely, dielectric relaxation spectroscopy.
authors.affiliation: CQE - Centro de Química Estrutural, Complexo I, IST, Universidade de Lisboa, Lisbon 1049-001, Portugal.
authors.forename: Elsa
authors.initials: E
authors.lastname: Mora
authors.affiliation: CQE - Centro de Química Estrutural, Complexo I, IST, Universidade de Lisboa, Lisbon 1049-001, Portugal. Electronic address: hdiogo@tecnico.ulisboa.pt.
authors.forename: Hermínio P
authors.initials: HP
authors.lastname: Diogo
authors.affiliation: CQFM - Centro de Química-Física Molecular and IN - Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal. Electronic address: mouraramos@tecnico.ulisboa.pt.
authors.forename: Joaquim J
authors.initials: JJ
authors.lastname: Moura Ramos
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D007052:Ibuprofen / Q000737:chemistry*; D007660:Ketoprofen / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D044367:Phase Transition; D013696:Temperature
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007660:Ketoprofen; D007052:Ibuprofen
keywords: amorphous; calorimetry (DSC); glass; glass transition; relaxation time; thermal analysis