Application of the normalized relative error distribution analysis for non-destructive quality control of drugs by Raman spectroscopy

Abstract

© 2019 John Wiley & Sons, Ltd. Development of drug quality control methods using non-invasive methods, in particular Raman spectroscopy, is an important task in the pharmaceutical industry. This paper presents a new approach to the analysis of drug spectra obtained with portable Raman spectrometers. It represents a normalized relative error distribution analysis (nReDA). The proposed method uses the Pearson residuals distribution statistics and, compared with the correlation method, allows increasing the screening sensitivity to foreign components that are not contained in the original sample, with the same resistance to changes in the noise distribution and the peak ratios. On the basis of the statistical data, the nReDA in some way is similar to the techniques such as principal component analysis, however, it requires a considerably less spectra to build a representative model and is suitable for comparing Raman spectra, having a noise other than the Gaussian one. The paper shows the prospects of the algorithm for creating a spectral library and solving the problem of transferring Raman libraries to a large number of spectrometers of the same type.