NIR-based approach to counterfeit-drug detection

There is no simple solution to the problem of counterfeit-drug detection. So-called “high-quality fakes” with proper composition are most difficult to reveal. Methods based only on quantitative determination of active ingredients are sometimes insufficient. A more general approach is to consider a remedy as a whole object, taking into account the complex composition of active ingredients and incipients, as well as manufacturing conditions (e.g., degree of drying). NIR measurement combined with chemometric data processing is an effective method but the superficial simplicity of its application may lead to wrong conclusions that undermine confidence in the technique. The main drawback of the NIR-based approach is the need to apply multivariate/chemometric data analysis in order to extract useful information from the acquired spectra.This article provides an overview of the experience of different research groups in NIR drug detection and highlights the main issues that should be taken into account. The common problems to be dealt with are:(1)each medicinal product should be carefully tested for batch-to-batch variability;(2)the selection of a specific spectral region and the data pre-processing method should be done for each type of medicine individually; and,(3)it is crucial to recognize counterfeits as well as to avoid misclassification of genuine samples.The real-world examples presented in the article illustrate these points.