Application of standardisation methods to correct the spectral differencesinduced by a fibre optic probe used for the near-infrared analysis of pharmaceutical tablets

Near infrared spectroscopy has become very popular in the pharmaceutical in dustry because of many important practical advantages. With the help of pow erful chemometric techniques, multivariate calibration models are developed , relating near-infrared spectra to the values to be modelled. However, bec ause of small instrumental differences between near-infrared spectrometers, a calibration model can only be used with spectra collected on the same in strument, which represents a serious limitation for the use of near-infrare d spectroscopy in the pharmaceutical industry. To deal with this important problem, a certain number of different standardisation approaches were prop osed in the literature. In this article, an application of instrument stand ardisation methods is presented, where two different data measurement modul es (internal measurement cell and external fibre optic module) of a near-in frared spectrometer must be standardised for the quantitative determination of an active compound in pharmaceutical tablets. (C) 1998 Elsevier Science B.V. All rights reserved.