Vibrational Spectroscopic Imaging

  • Sara J. Fraser-Miller
  • Jukka Saarinen
  • Clare J. StrachanEmail author
Part of the Advances in Delivery Science and Technology book series (ADST)


Vibrational spectroscopy, which probes vibrations within and between molecules, may be divided into four classes: mid-infrared (MIR, also referred to as just infrared (IR)), near-infrared (NIR), terahertz/far-infrared (FIR), and Raman. These techniques, described in earlier chapters, have several features in common: they are rapid, non-destructive, and label-free and can yield information-rich data about both the chemical and physical (e.g. solid state form) properties of samples. NIR, IR and terahertz spectroscopies probe the absorption of infrared light of increasing wavelength (from NIR to terahertz regions). In contrast, Raman spectroscopy is based on a scattering phenomenon and may be used to probe vibrations that occur in both the MIR and terahertz regions. These techniques have become widespread for drug and dosage form characterisation during, for example, synthesis and pharmaceutical processing.

Often it is important to know the location of components within a sample. Thus, spectrometers can be coupled with devices (e.g. microscope, array detector) for spatially resolved analysis. With various setups, vibrational spectroscopic imaging may be performed on the macro-, micro-, and even nano-scales. The continuing fundamental advances in spectroscopic imaging technology are facilitating the increasingly widespread adoption of vibrational spectroscopic imaging for diverse analyses in the pharmaceutical setting.

In this chapter vibrational spectroscopic imaging methods based on IR, NIR, terahertz, and Raman signals will be described. The chapter begins with a description of the principles of the analytical methods and their variants, followed by an introductory description of spectroscopic data analysis methods. Finally, the pharmaceutical application of these methods will be described throughout the ‘lifecycle’ of the drug. This includes raw material (drug and excipient) and dosage form characterization, drug dissolution/release analysis, and imaging during drug delivery.


Mid-infrared (IR) Near infrared (NIR) Raman Terahertz Imaging Microscopy Mapping Vibrational spectroscopy 


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Copyright information

© Controlled Release Society 2016

Authors and Affiliations

  • Sara J. Fraser-Miller
    • 1
  • Jukka Saarinen
    • 1
  • Clare J. Strachan
    • 1
    Email author
  1. 1.Formulation and Industrial Pharmacy Unit, Division of Pharmaceutical Chemistry and Technology, Faculty of PharmacyUniversity of HelsinkiHelsinkiFinland

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