title: Solid-state vitrification of crystalline griseofulvin by mechanical milling.
abstract: The thermodynamic, dynamic, and structural changes of crystalline griseofulvin upon high-energy ball milling at room temperature have been studied. The investigations have been performed by differential scanning calorimetry (DSC), dielectric relaxation spectroscopy, and powder X-ray diffraction. The results indicate that this compound undergoes a direct crystal-to-glass transformation upon milling, whereas no glass transition can be clearly detected upon heating because of the exceptional sub-glass transition temperature (T(g) ) recrystallization of the milled sample. This intrinsic difficulty for characterizing the glassy state has been overcome using three independent strategies: (i) comparison of the evolutions upon milling of both the crystalline powder and the quenched liquid, (ii) use of fast DSC to delay the recrystallization event, and (iii) search for dielectric β relaxations typical of glasses in the milled compound.
authors.affiliation: Université Lille Nord de France, USTL Unité Matériaux et Transformations, UMR CNRS 8207, F-59650 Villeneuve d'Ascq, France. jean-francois.willart@univ-lille1.fr
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Willart
authors.forename: Laurent
authors.initials: L
authors.lastname: Carpentier
authors.forename: Florence
authors.initials: F
authors.lastname: Danède
authors.forename: Marc
authors.initials: M
authors.lastname: Descamps
mesh_terms: D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D004339:Drug Compounding; D006118:Griseofulvin / Q000737:chemistry*; D013696:Temperature; D058989:Vitrification; D014961:X-Ray Diffraction
chemical_list: D006118:Griseofulvin