title: Estimation of crystallinity of trehalose dihydrate microspheres by usage of terahertz time-domain spectroscopy.
abstract: Crystalline state of pharmaceutical materials is of great importance in the preparation of pharmaceutics because their physicochemical properties affect bioavailability, quality of products, therapeutic level, and manufacturing process. In this study, we have estimated the crystallinity of trehalose dihydrate microspheres by measuring terahertz (THz) spectroscopy. The commercially available trehalose dihydrate takes in general a crystalline state, but trehalose dihydrate microspheres prepared by using spray-drying method are in an amorphous state. We have prepared amorphous anhydrous trehalose by using melt-quenched method from crystalline trehalose dihydrate. We have measured the absorbance of trehalose dihydrate containing amorphous anhydrous trehalose (0%, 25%, 50%, 75%, and 100%) using THz time-domain spectroscopy (THz-TDS) to prepare calibration curves. Using the calibration curves, we have estimated the crystallinity of trehalose dihydrate microspheres prepared by using spray-drying method. Our results suggest that THz-TDS is well suited to distinguish crystallinity differences in pharmaceutical compounds.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Issei
authors.initials: I
authors.lastname: Takeuchi
authors.forename: Keishiro
authors.initials: K
authors.lastname: Tomoda
authors.forename: Takehisa
authors.initials: T
authors.lastname: Nakajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terada
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuroda
authors.forename: Kimiko
authors.initials: K
authors.lastname: Makino
mesh_terms: D002138:Calibration; D002626:Chemistry, Pharmaceutical; D018360:Crystallography, X-Ray; D005079:Excipients / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D013607:Tablets; D013678:Technology, Pharmaceutical / Q000379:methods* / Q000592:standards; D055068:Terahertz Spectroscopy / Q000592:standards; D013997:Time Factors; D014199:Trehalose / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D005079:Excipients; D013607:Tablets; D014867:Water; D014199:Trehalose