Quantitative analysis of a pharmaceutical formulation: Performance comparison of different handheld near-infrared spectrometers

In the present communication calibration spectra of a solid pharmaceutical formulation consisting of two excipients and three active ingredients, acetylsalicylic acid (ASA), ascorbic acid (ASC) and caffeine (CAF), have been measured with four handheld NIR spectrometers based on different monochromator principles and have subsequently been used to develop partial least squares (PLS) models for the quantitative determination of the active ingredients. Taking into account the instrumental and spectral peculiarities of the four instruments and the three analytes, respectively, the detailed analysis of the calibration parameters and the prediction accuracy for a test sample set then allowed to compare the performance of the different spectrometers for the analytical problem under investigation.