Author: Šašić, Slobodan

Source: Applied Spectroscopy, Volume 61, Issue 3, Pages 52A-64A and 239-347 (March 2007) , pp. 239-250(12)

Publisher: Society for Applied Spectroscopy

Abstract:

This study reports on the application of Raman and near-infrared (NIR) imaging techniques for determining the spatial distribution of all (five) components in a common type of pharmaceutical tablet manufactured in two different ways. Multivariate chemical images were produced as principal component (PC) scores, while univariate images were produced by using the most unique spectra selected by the orthogonal projection approach (OPA), a searching algorithm. Multivariate Raman images were obtained for all five components in both tablets, while only two or three components could be imaged with the NIR instrument. Very interesting PC results are reported that in effect cast doubt on the effectiveness of the established criteria for determining signal-related PCs in the Raman data. PCA has been found to be indispensable for imaging the minor components using the Raman data. Significant similarity between the multivariate and univariate chemical images has been noted despite there being considerable spectral overlap within the Raman and, especially, within the NIR mapping data sets. Gray-scale images are carefully thresholded, which allowed for quantitative comparison of the obtained binarized images. A thorough discussion is given on the problems and approximations needed for producing composite images.

Keywords: CHEMICAL IMAGING; RAMAN; NEAR-INFRARED SPECTROSCOPY; NIR SPECTROSCOPY; PRINCIPAL COMPONENT ANALYSIS; PCA; TABLETS; PHARMACEUTICALS; CHEMOMETRICS

Document Type: Research article

DOI: http://dx.doi.org/10.1366/000370207780220769

Affiliations: 1: Pfizer Global Research and Development, Ramsgate Road, Sandwich CT13 9NJ, UK

Publication date: 2007-03-01

More about this publication?

• The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge.
  
  Previously published as Bulletin (Society for Applied Spectroscopy)
• Editorial Board
• Information for Authors
• Submit a Paper
• Subscribe to this Title
• Membership Information
• Request copyrighted SAS materials
• Spectroscopic Nomenclature
• Focus Compendium
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Analytical Chemistry
• By this author: Šašić, Slobodan

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers