title: Structural and analytical characterization of three hydrates and an anhydrate form of risedronate.
abstract: Four hydration states are reported for Risedronate monosodium. A single-crystal X-ray structure determination is provided as proof of assignment for the monohydrate, hemi-pentahydrate, and variable hydrate forms. The structure provided for the anhydrate form was determined through simulating annealing calculations and subsequent Reitveld refinement of a high-quality X-ray powder diffraction patterns Favorable comparisons of experimentally obtained X-ray powder patterns are made to those generated from the single crystal data. Characteristic infrared, Raman, and NMR spectra are provided and discussed for each form as are thermal analysis profiles. In addition, photomicrographs are provided for each of the forms isolated for this study. The hemi-pentahydrate is demonstrated to be the equilibrium form at room temperature and 37 degrees C, in the presence of water.
authors.affiliation: Procter & Gamble Pharmaceuticals, Inc., P.O. Box 191, Norwich, New York 13815, USA. redmanfurey.nl@pg.com
authors.forename: Nancy
authors.initials: N
authors.lastname: Redman-Furey
authors.forename: Michael
authors.initials: M
authors.lastname: Dicks
authors.forename: Adrienne
authors.initials: A
authors.lastname: Bigalow-Kern
authors.forename: R Thomas
authors.initials: RT
authors.lastname: Cambron
authors.forename: Gwen
authors.initials: G
authors.lastname: Lubey
authors.forename: Cathy
authors.initials: C
authors.lastname: Lester
authors.forename: Dana
authors.initials: D
authors.lastname: Vaughn
mesh_terms: D000042:Absorption; D018360:Crystallography, X-Ray; D004055:Differential Thermal Analysis; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*; D005079:Excipients; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D000068296:Risedronic Acid; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D005079:Excipients; D000068296:Risedronic Acid; D012968:Etidronic Acid