Non-invasive confirmation of the identity of tablets by near-infrared spectroscopy

Calibration of non-invasive near-infrared (NIR) analysis for measurements in diffuse reflectance and transmittance was conducted to confirm the identity of different film-coated and uncoated tablets. NIR-spectra of both sides of the intact tablets were recorded in diffuse reflectance. The second derivation of the spectra was computed and spectral matching was calibrated. A restricted wavelength range was proposed to recognize the tablets independently of the presentation over the NIR-light beam. For transmittance measurement, the tablets were arranged in groups according to their similarities. All calibrations were tested against an independent set of sample spectra. The NIR-method proved to be fast and effective.