title: Application of terahertz absorption spectroscopy to evaluation of aging variation of medicine.
abstract: The absorption spectra of three kinds of medicines both before and after the expiration date: Amlodin OD(®) (5 mg), Basen OD(®) (0.2 mg) and Gaster D(®) (10 mg) have been measured by terahertz time domain spectroscopy (THz-TDS). All the medicines show some differences in the THz absorption spectra between medicines before and after the expiration dates. X-Ray powder diffraction (XRD) studies of all medicines suggest that the polymorph of the main effective compound is not changed before and after the expiration date. Therefore, the differences in the THz spectra between medicines before and after the expiration dates arise from aging variation of diluting agents and/or from modifications of intermolecular interaction between the effective compounds and diluting agents.
authors.affiliation: Nagahama Institute of Bio-science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan. m_kawase@nagahama-i-bio.ac.jp
authors.forename: Masaya
authors.initials: M
authors.lastname: Kawase
authors.forename: Tadashi
authors.initials: T
authors.lastname: Saito
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ogawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Uejima
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Hatsuda
authors.forename: Sonoyo
authors.initials: S
authors.lastname: Kawanishi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hirotani
authors.forename: Michiaki
authors.initials: M
authors.lastname: Myotoku
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikeda
authors.forename: Hiroki
authors.initials: H
authors.lastname: Konishi
authors.forename: Ikumi
authors.initials: I
authors.lastname: Iga
authors.forename: Junji
authors.initials: J
authors.lastname: Yamakawa
authors.forename: Seizi
authors.initials: S
authors.lastname: Nishizawa
authors.forename: Kohji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tani
mesh_terms: D000042:Absorption; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000737:chemistry*; D055068:Terahertz Spectroscopy / Q000379:methods*; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D004364:Pharmaceutical Preparations