title: Monitoring the recrystallisation of amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering.
abstract: In this paper we present a fast model system for monitoring the recrystallization of quench-cooled amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering. The use of these two methods enables comparison between surface and bulk crystallization. Non-ordered mesoporous silica micro-particles were added to the system in order to alter the rate of crystallization of the amorphous xylitol. Raman measurements showed that adding silica to the system increased the rate of surface crystallization, while X-ray measurements showed that the rate of bulk crystallization decreased. Using this model system it is possible to measure fast changes, which occur in minutes or within a few hours. Raman-spectroscopy and wide-angle X-ray scattering were found to be complementary techniques when assessing surface and bulk crystallization of amorphous xylitol.
authors.affiliation: Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki, Finland. Electronic address: emmi.palomaki@helsinki.fi.
authors.forename: Emmi
authors.initials: E
authors.lastname: Palomäki
authors.affiliation: Department of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland.
authors.forename: Patrik
authors.initials: P
authors.lastname: Ahvenainen
authors.affiliation: Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki, Finland.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ehlers
authors.affiliation: Department of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Svedström
authors.affiliation: Department of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Huotari
authors.affiliation: Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Yliruusi
mesh_terms: D003460:Crystallization; D012822:Silicon Dioxide / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction / Q000379:methods*; D014993:Xylitol / Q000737:chemistry*
chemical_list: D012822:Silicon Dioxide; D014993:Xylitol
keywords: Amorphous; Crystallization; Ibuprofen (PubChem CID 3672); Indomethacin (PubChem CID 3715); Non-ordered mesoporous silica; Raman spectrometry; Silica (PubMed CID 24261); Wide-angle X-ray scattering; Xylitol; Xylitol (PubChem CID 6912)