Near infrared spectroscopy in the study of polymorphic transformations

Marcel Blanco, Manel Alcalá, Josep M. González, Ester Torras

Research output: Contribution to journalArticleResearchpeer-review

48 Citations (Scopus)


The potential of near infrared (NIR) spectroscopy for the characterization of polymorphs in the active principle of a commercial formulation prior to and after the manufacturing process was assessed. Polymorphism in active principles is extremely significant to the pharmaceutical industry. Polymorphic changes during the production of commercial pharmaceutical formulations can alter some properties of the resulting end-products. Multivariate curve resolution-alternating least squares (MCR-ALS) methodology was used to obtain the "pure" NIR spectrum for the active principle without the need to pretreat samples. This methodology exposed the polymorphic transformation of Dexketoprofen Trometamol (DKP) in both laboratory and production samples obtained by wet granulation. No polymorphic transformation, however, was observed in samples obtained by direct compaction. These results were confirmed using by X-ray powder diffractometry (XRD) and differential scanning calorimetry (DSC) measurements. Pure crystalline polymorphs of DKP were available in the laboratory but amorphous form was not, nevertheless the developed methodology allows the identification of amorphous and crystal forms in spite of the lack of pure DKP. © 2006 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)262-268
JournalAnalytica Chimica Acta
Issue number2
Publication statusPublished - 17 May 2006


  • Differential scanning calorimetry
  • Drugs
  • Granulation
  • Near-infrared spectroscopy
  • Polymorphism
  • X-ray powder diffractometry


Dive into the research topics of 'Near infrared spectroscopy in the study of polymorphic transformations'. Together they form a unique fingerprint.

Cite this