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

Tracy O. Ehiwe; Bruce D. Alexander; John C. Mitchell; Martin J. Snowden; Laura J. Waters

doi:10.1016/j.jpha.2015.12.002

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

Tracy O. Ehiwe, Bruce D. Alexander, John C. Mitchell, Martin J. Snowden, Laura J. Waters

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

This study investigated the development of a novel approach to surface characterization 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 (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 SFN 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 2.43×10⁻² s⁻¹.

Original language	English
Pages (from-to)	179-183
Number of pages	5
Journal	Journal of Pharmaceutical Analysis
Volume	6
Issue number	3
Early online date	8 Jan 2016
DOIs	https://doi.org/10.1016/j.jpha.2015.12.002
Publication status	Published - Jun 2016

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@article{1fb5491c8dae4332a2eb6ac1f09e0371,

title = "Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy",

abstract = "This study investigated the development of a novel approach to surface characterization of drug polymorphism and the extension of the capabilities of this method to perform {\textquoteleft}real time{\textquoteright} in situ measurements. This was achieved using diffuse reflectance visible (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 SFN 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 2.43×10−2 s−1.",

keywords = "Differential scanning calorimetry, Diffuse reflectance visible spectroscopy, Polymorphic transformation, Powder X-ray diffraction, Sulfanilamide",

author = "Ehiwe, {Tracy O.} and Alexander, {Bruce D.} and Mitchell, {John C.} and Snowden, {Martin J.} and Waters, {Laura J.}",

note = "Accepted and Epub before April 1st 2016 HN 27/10/2017",

year = "2016",

month = jun,

doi = "10.1016/j.jpha.2015.12.002",

language = "English",

volume = "6",

pages = "179--183",

journal = "Journal of Pharmaceutical Analysis",

issn = "2095-1779",

publisher = "Xi'an Jiaotong University",

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T1 - Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy

AU - Ehiwe, Tracy O.

AU - Alexander, Bruce D.

AU - Mitchell, John C.

AU - Snowden, Martin J.

AU - Waters, Laura J.

N1 - Accepted and Epub before April 1st 2016 HN 27/10/2017

PY - 2016/6

Y1 - 2016/6

N2 - This study investigated the development of a novel approach to surface characterization 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 (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 SFN 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 2.43×10−2 s−1.

AB - This study investigated the development of a novel approach to surface characterization 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 (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 SFN 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 2.43×10−2 s−1.

KW - Differential scanning calorimetry

KW - Diffuse reflectance visible spectroscopy

KW - Polymorphic transformation

KW - Powder X-ray diffraction

KW - Sulfanilamide

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DO - 10.1016/j.jpha.2015.12.002

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EP - 183

JO - Journal of Pharmaceutical Analysis

JF - Journal of Pharmaceutical Analysis

SN - 2095-1779

IS - 3

ER -

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

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