Andrea C Schmidt1. 1. Department of Pharmaceutical Technology, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria. andrea.schmidt@uibk.ac.at
Abstract
PURPOSE: This report is the résumé of a comprehensive investigation on the solid-state properties and the crystal polymorphism of the structurally homogenous class of local anesthetic drugs. The goal is to explore the relationship between crystal polymorphism and molecular structural features. METHODS: A salt form (mostly the hydrochloride) as well as the free base of 24 local anesthetics has been characterized by means of thermomicroscopy, differential scanning calorimetry, pycnometry, Fourier transform infrared, Fourier transform Raman, and solid-state NMR spectroscopies, as well as X-ray diffraction methods (single crystal, powder). RESULTS: Based on the thermochemical data, the relative thermodynamic stabilities of the different crystal forms of each polymorphic system were evaluated and visualized as semiquantitative energy/temperature diagrams. CONCLUSION: This study is the first step in recognizing relationships between the structure and the solid-state properties within this limited group of active substances with common structural elements. The results clearly show that there are certain relationships, but, to understand the phenomenological behavior in more detail on a molecular level, more structural information must be collected and analyzed by computational methods.
PURPOSE: This report is the résumé of a comprehensive investigation on the solid-state properties and the crystal polymorphism of the structurally homogenous class of local anesthetic drugs. The goal is to explore the relationship between crystal polymorphism and molecular structural features. METHODS: A salt form (mostly the hydrochloride) as well as the free base of 24 local anesthetics has been characterized by means of thermomicroscopy, differential scanning calorimetry, pycnometry, Fourier transform infrared, Fourier transform Raman, and solid-state NMR spectroscopies, as well as X-ray diffraction methods (single crystal, powder). RESULTS: Based on the thermochemical data, the relative thermodynamic stabilities of the different crystal forms of each polymorphic system were evaluated and visualized as semiquantitative energy/temperature diagrams. CONCLUSION: This study is the first step in recognizing relationships between the structure and the solid-state properties within this limited group of active substances with common structural elements. The results clearly show that there are certain relationships, but, to understand the phenomenological behavior in more detail on a molecular level, more structural information must be collected and analyzed by computational methods.
Authors: W D Sam Motherwell; Herman L Ammon; Jack D Dunitz; Alexander Dzyabchenko; Peter Erk; Angelo Gavezzotti; Detlef W M Hofmann; Frank J J Leusen; Jos P M Lommerse; Wijnand T M Mooij; Sarah L Price; Harold Scheraga; Bernd Schweizer; Martin U Schmidt; Bouke P van Eijck; Paul Verwer; Donald E Williams Journal: Acta Crystallogr B Date: 2002-07-30
Authors: Hyeoncheol Hwang; Jihong Park; Won Kyung Lee; Woo Hyung Lee; Ja-Ho Leigh; Jin Joo Lee; Sun G Chung; Chaiyoung Lim; Sang Jun Park; Keewon Kim Journal: Ann Rehabil Med Date: 2016-02-26