title: Terahertz spectroscopy to identify the polymorphs in freeze-dried Mannitol.
abstract: We show how terahertz time-domain spectroscopy (THz-TDS) in the range from 0.1 to 7.5 THz can be used to identify the polymorphs of Mannitol, a frequently used excipient in the freeze drying industry. The results are subsequently used to study the effect that different freeze drying techniques have on the formation of these polymorphs. We find that, depending on the freeze-drying technique, the Mannitol either crystallizes in the delta form, or in a mixture of both the delta form and the beta form. The results are in agreement with conventional X-ray diffraction measurements used to identify the polymorphs.
authors.affiliation: Department of Imaging Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands. r.chakkittakandy@tudelft.nl
authors.forename: Reshmi
authors.initials: R
authors.lastname: Chakkittakandy
authors.forename: Jos A W M
authors.initials: JA
authors.lastname: Corver
authors.forename: Paul C M
authors.initials: PC
authors.lastname: Planken
mesh_terms: D003460:Crystallization; D005079:Excipients; D005612:Freeze Drying; D007536:Isomerism; D008353:Mannitol / Q000737:chemistry*; D055068:Terahertz Spectroscopy / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D005079:Excipients; D008353:Mannitol