Computing and Library Services - delivering an inspiring information environment

Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy

Ehiwe, Tracy O., Alexander, Bruce D., Mitchell, John C., Snowden, Martin J and Waters, Laura J. (2016) Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy. Journal of Pharmaceutical Analysis, 6 (3). pp. 179-183. ISSN 2095-1779

[img] PDF (Accepted manuscript) - Published Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (833kB)


This study investigated the development of a novel approach to surface characterisation of drug polymorphism and the extension of the capabilities of this method to perform ‘real time’ in situ measurements. This was achieved using diffuse reflectance visible spectroscopy (DRV spectroscopy) and dye deposition, using the pH sensitive dye, thymol blue (TB). Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide (SFN) were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of sulfanilamide polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model (R2 = 0.992), giving a rate constant of 2.43 x 10−2 s−1.

Item Type: Article
Subjects: Q Science > QD Chemistry
Schools: School of Applied Sciences
Related URLs:
Depositing User: Laura Waters
Date Deposited: 11 Jan 2016 09:27
Last Modified: 28 Aug 2021 17:31


Downloads per month over past year

Repository Staff Only: item control page

View Item View Item

University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©