title: Monitoring of Pentoxifylline Thermal Behavior by Novel Simultaneous Laboratory Small and Wide X-Ray Scattering (SWAXS) and Differential Scanning Calorimetry (DSC).
abstract: The thermal and structural evolutions associated to active pharmaceutical ingredient (API) purity are monitored using a laboratory instrument (S3-MicroCaliX) allowing simultaneous time-resolved X-ray scattering at both wide and small angles (SWAXS) as a function of temperature. This is performed simultaneously with differential scanning calorimetric (DSC) that is carried out in the same apparatus at scanning rate of 2 K/min on the same sample in the range from 20° to 200°C. We have studied simultaneous thermal and structural properties of pentoxifylline, as an active pharmaceutical ingredient (API), for its purity quality control. We have found a satisfying API purity, due to obtained melting temperature and enthalpy values, which are in a well agreement with literature. We have also found that the combination of these techniques allows the thermal monitoring of scanning rates of 2 K/min, continuously without the need for static thermal equilibration, particularly for X-ray spectra. Hence, DSC and SWAXS allowing better identification of the structural thermal events recorded by following of the phase transitions simultaneously. This interpretation is much better possible when X-ray scattering at small and wide angles is coupled with DSC from the same sample. Hence, as a laboratory tool, the method presents a reproducible thermal and crystallographic API purity quality control of non-complex samples, as crucial information for pharmaceutical technology.
authors.affiliation: Central European Research Infrastructure Consortium (CERIC-ERIC), Trieste, Italy.|Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
authors.forename: Aden
authors.initials: A
authors.lastname: Hodzic
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kriechbaum
authors.affiliation: Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria.
authors.forename: Simone
authors.initials: S
authors.lastname: Schrank
authors.affiliation: GL-Pharma GmbH, Lannach, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Reiter
mesh_terms: D002152:Calorimetry, Differential Scanning / Q000379:methods*; D010431:Pentoxifylline / Q000737:chemistry*; D012542:Scattering, Radiation; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D010431:Pentoxifylline