ABSTRACT
Near-infrared chemical imaging (NIRCI) characterizes pharmaceutical solid oral dosage
forms bymeasuringmolecular absorption properties in the near-infrared region in a spatially
resolved manner. Molecular absorptions in the near-infrared are primarily due to overtones
and combination bands of fundamental molecular vibrational frequencies of C-H, N-H and
O-H bonds. This spectral information can be used to characterize the chemical composition
of organic material. Single point near-infrared techniques, which result in a single spectrum
that is averaged over the entire sample, provide information about the identity and abundance
of the chemical components of a sample. In addition to this information,NIRCI characterizes
spatial distribution by generating tens of thousands of spatially resolved spectra. NIRCI in
essence provides a chemical picture of the sample. The technique combines chemical and
image analyses, allowing for the characterization of chemical distributions (level of heter-
ogeneity) and also for morphological analysis of the sample. The size and shape of single
component domains, granules, or other particles within the sample can be measured.
