• granulation;
  • physical characterization;
  • multivariate analysis;
  • near-infrared spectroscopy;
  • powder technology;
  • processing;
  • automation;
  • microwave sensing


Roller compaction is commonly used in the pharmaceutical and nutraceutical industries to increase and narrow the size distribution of a particulate material, making it easier to process. Both the moisture content of the material and the density of the roller compacted ribbon affect the uniformity and physical properties of the resultant granules. Without process analytical technologies, these parameters cannot be determined on-line or in real time. In this study, the more commonly used near-infrared (NIR) spectroscopy was compared and contrasted with microwave resonance for the determination of roller-compacted ribbons' envelope density and moisture content. Results indicate that microwave resonance can offer improved accuracy, robustness, and ease-of-use compared with NIR spectroscopy for these property measurements. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:1895–1904, 2013