Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Pharm Sci. 2003 Nov;92(11):2260-71.

Comparison of the four anhydrous polymorphs of carbamazepine and the crystal structure of form I.

Author information

  • 1Department of Chemistry and the Macromolecular Science and Engineering Program, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA.

Abstract

For decades, carbamazepine (CBZ) has served as a model compound for groups engaged in the study of crystal polymorphism. Despite considerable effort, crystal structures for only three of its four anhydrous forms have previously been determined. Herein, we report the first single crystal X-ray structure of the high temperature modification of CBZ (form I). Form I crystallizes in a triclinic cell (P-1) having four inequivalent molecules with the following lattice parameters: a = 5.1705(6), b = 20.574(2), c = 22.245(2) A, alpha = 84.12(4), beta = 88.01(4), and gamma = 85.19(4) degrees. Furthermore, we compare the physical properties of the four anhydrous polymorphs of CBZ, including the first comprehensive characterization of form IV. Substantial differences are seen among these forms by powder X-ray diffraction, infrared spectroscopy, thermomicroscopy, and differential scanning calorimetry. These data are correlated to their respective crystal structures for the first time. We have found that all polymorphs possess identical strong hydrogen bonding patterns, similar molecular conformations, and stabilities that are within 0.7 kcal/mol of each other.

Copyright 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:2260-2271, 2003

PMID:
14603511
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for John Wiley & Sons, Inc.
    Loading ...
    Write to the Help Desk