title: Estimation of Crystallinity of Nifedipine-Polyvinylpyrrolidone Solid Dispersion by Usage of Terahertz Time-Domain Spectroscopy and of X-Ray Powder Diffractometer.
abstract: Crystalline state of pharmaceutical materials is of great importance in preparation of pharmaceutics, because their physicochemical properties affect bioavailability, quality of products, therapeutic level and manufacturing process. In this study, we have estimated time-dependent changes of nifedipine in nifedipine-polyvinylpyrrolidone (PVP) solid dispersion by measuring terahertz time-domain spectroscopy (THz-TDS) and by X-ray powder diffractometry (XRPD), and compared their correlativity. Crystallinity of nifedipine-PVP solid dispersion was changed by storing the amorphous sample at 25°C-75°C and relative humidity of over 80% for 0.25-24.00 h. To compare the results of two types of measurements, we have used a general method of linear regression analysis. Crystallinities estimated using THz-TDS were plotted on the x-axis and that of XRPD were on the y-axis. From the result of the calculation, the correlativity of them was confirmed. THz-TDS has the capability of becoming the replacement of XRPD.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Issei
authors.initials: I
authors.lastname: Takeuchi
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Kemmaro
authors.initials: K
authors.lastname: Shimakura
authors.affiliation: Otsuka Electronics Company, Ltd., Development and Engineering Division, Osaka 573-1132, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuroda
authors.affiliation: Center for Drug Delivery Research, Tokyo University of Science, Chiba 278-8510, Japan; Center for Physical Pharmaceutics, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510, Japan; Center for Drug Delivery Research, Tokyo University of Science, Chiba 278-8510, Japan; Center for Physical Pharmaceutics, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Goto
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba 278-8510, Japan; Center for Drug Delivery Research, Tokyo University of Science, Chiba 278-8510, Japan; Center for Physical Pharmaceutics, Tokyo University of Science, Chiba 278-8510, Japan. Electronic address: makino@rs.noda.tus.ac.jp.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Makino
mesh_terms: D003460:Crystallization / Q000379:methods; D006813:Humidity; D009543:Nifedipine / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*; D011208:Powders / Q000737:chemistry*; D012044:Regression Analysis; D013696:Temperature; D055068:Terahertz Spectroscopy / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods; D014965:X-Rays
chemical_list: D011208:Powders; D011205:Povidone; D009543:Nifedipine
keywords: X-ray powder diffractometer; amorphous; crystallinity; nifedipine; nondestructive analysis; polyvinylpyrrolidone; solid dispersion; spectroscopy; spray drying; terahertz time-domain spectroscopy