Quality Control of Multi-Component, Intact Pharmaceutical Tablets with Three Different Near-Infrared Apparatuses

The purpose of this study was to develop a robust and versatile near infrared (NIR) analysis protocol for the quality control of intact tablets containing two active pharmaceutical ingredients, acetylsalicylic acid (ASA) and caffeine, as well as three excipients. Reference samples were prepared and a calibration model built for each apparatus. All components of the formulation were characterized by transmission measurements with NIR spectroscopy (NIRS). The study was performed with three different Fourier transform NIR apparatuses and chemometric models. Calibration was carried out by the partial least squares regression method and a pre-processing technique to optimize the efficiency of the models. High performance liquid chromatography was the reference method for obtaining active pharmaceutical ingredient concentration values used in model building. It also served as a reference for chemometric model validation. Eighteen samples were analyzed by chemometric modeling to predict each component's concentration. Four out of five ingredients were quantified precisely with the three chemometric models developed. ASA quantification uncertainty ranges were between 1.0 and 1.1%, and the average error was less than 5% for caffeine. More than 99.9% of tablet content were analyzed and quantified. The results show that a versatile in-line or at-line NIRS method, with three different chemometric models built from three different acquisition apparatuses, can be developed without sample preparation for pharmaceutical tablet quality control of existing products.