A novel identification system for counterfeit drugs based on portable Raman spectroscopy

• A novel identification system for screening of the counterfeit drugs is proposed.
• The strategy provides an alternative.
• The strategy is demonstrated with high rapidity, accuracy and cost-effectiveness.

Quick inspection methods for counterfeit drugs are of vital necessity. In this study, the feasibility of portable Raman spectroscopy as an analytical method together with a novel identification system for fake drugs detection is demonstrated. The rapid and convenient identification system based on modified local straight-line screening (LSLS) and principal component analysis (PCA) is developed to distinguish counterfeit from authentic. LSLS algorithm was originally designed to detect synthetic drug(s) adulterated in herbal medicines based on infrared spectroscopy. In order to adapt the LSLS method for the detection of the suspected counterfeit drugs based on portable Raman spectroscopy, modification of weighting is made in this paper to obtain the low false positive rate (FPR) and low false negative rate (FNR). The proposed identification system has been benchmarked by 7 kinds (40 batches) of hypoglycemic tablets and 12 common pharmaceutical excipients. The total sensitivity, specificity and accuracy are 96.77%, 97.48% and 96.35% respectively. The results indicate that the identification system is appropriate for the on-site preliminary screening of the suspected counterfeit drugs.