Table of Contents
ISRN Chromatography
Volume 2012 (2012), Article ID 892806, 6 pages
http://dx.doi.org/10.5402/2012/892806
Research Article

Quantifying Solid-State Mixtures of Crystalline Indomethacin by Raman Spectroscopy Comparison with Thermal Analysis

1Department of Pharmaceutical Sciences, School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Avenue, Boston, MA 02115, USA
2School of Pharmacy and Health Professions, Creighton University, Hixson-Lied Building. 152, 2500 California Plaza, Omaha, NE 68178, USA
3Department of Chemistry and Chemical Biology, Northeastern University, 414 Hurtig Hall, Boston, MA 02115, USA

Received 7 December 2011; Accepted 25 December 2011

Academic Editor: R. Nageswara Rao

Copyright © 2012 Eman Atef et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper investigates Raman spectroscopy as a quick and reliable method to quantify the alpha (α) and gamma (γ) polymorphic forms of indomethacin compared to differential scanning calorimetry (DSC). Binary mixtures with different ratios of α and γ indomethacin were prepared and analyzed by Raman and DSC. The Raman method was found to be more reliable and superior compared to DSC. The partial conversion of the alpha to gamma polymorphic form during the DSC measurement was the major limitation for the use of full DSC as a quantitative method and resulted in difference between the calculated and measured enthalpy of both polymorphic forms.