Particle size spectral libraries

This procedure can consist of different stages with one sublibrary being constructed at each stage. The first one enables the identification of the product within an ample library, a second defines a characteristic that produces an important variability in the spectra (e.g. particle size) and a third defines a smaller spectral variability (difference in the content of impurities, origin of manufacture, etc.). 

NIRS is useful for the analysis of both raw materials and finished dosage forms. Qualitative determination of pharmaceutical raw materials using NIRS was reported as early as 1982. The largest variations in commercially produced excipients and actives appear to be in moisture content and particle size. These parameters may be monitored by NIRS with relative ease. Incoming substances may be tested for immediate identity confirmation on the receiving dock by inserting a fiber optic probe directly into the barrel. Spectral data for each lot of material purchased may be saved and added to the growing spectral reference library. 

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