A process analytical technology approach based on near infrared spectroscopy: tablet hardness, content uniformity, and dissolution test measurements of intact tablets

J Pharm Sci. 2006 Oct;95(10):2137-44. doi: 10.1002/jps.20653.


Near infrared spectroscopy (NIRS) is a nondestructive analytical technique that enables simultaneous measurements of chemical composition (viz. the content in active pharmaceutical ingredient, API) and various physical properties (viz. tablet hardness and dissolution profile) in pharmaceutical tablets. In this work, partial least squares (PLS) calibration models and discriminant partial least squares (DPLS) classification models were constructed by using calibration sets consisting of laboratory samples alone. The laboratory samples were mixtures of the API and excipients that were pressed into tablets. API content, tablet hardness, and dissolution measurements of intact tablets were made by using three different calibration models that are fast--results can be obtained within a few seconds--, simple and robust--they involve minimal analyst intervention--, and clean--they use no toxic reagent and produce no toxic waste. Based on the results, the proposed NIR method is an effective alternative to current reference methods for the intended purpose. The advantages provided by NIR spectroscopy in this context confirm its potential for inclusion in process analytical technologies in the pharmaceutical industry.

Publication types

  • Validation Study

MeSH terms

  • Calibration
  • Chemistry, Pharmaceutical
  • Excipients / chemistry
  • Hardness
  • Least-Squares Analysis
  • Models, Chemical
  • Pregnenediones / analysis
  • Pregnenediones / chemistry
  • Solubility
  • Spectroscopy, Near-Infrared
  • Tablets / analysis*
  • Tablets / chemistry*


  • Excipients
  • Pregnenediones
  • Tablets
  • deflazacort