Identification and quantitation assays for intact tablets of two related pharmaceutical preparations by reflectance near-infrared spectroscopy: validation of the procedure

Quantitative analysis based on near-infrared (NIR) spectroscopy uses indivi dual calibration equations for each sample studied because of the need to m odel all possible chemical and physical variability sources. A NIR method, using a fibre optical probe, for the analysis of two different and related pharmaceuticals from two different production steps (cores and tablets) is studied. Both pharmaceuticals have the same active principle and similar ex cipients, but with different nominal concentration values. The pharmaceutic als are identified by comparison using a second-derivative spectral library ; an identification procedure consisting of two-steps (cascade) library: co rrelation coefficient followed by maximum distance in wavelength space is p roposed. Once a sample has been positively identified, the active principle is quantified with partial least-squares regression (PLSR) using a sole an d global calibration. The proposed method was validated for use as a contro l method, and for this purpose selectivity of the identification process, a nd the repeatability, intermediate precision, accuracy, linearity, and robu stness of the active principle quantitation, were assessed. (C) 2000 Elsevi er Science B.V. All rights reserved.