Pharmaceutical counterfeiting is becoming a significant issue in the healthcare community as well as for the pharmaceutical industry worldwide. A rapid screening technique such as near infrared (NIR) spectroscopy could aid in the search for and identification of counterfeit drugs. In the present paper, five generic vitamin tablets with different active ingredient content, produced by different manufacturers, were used as examples to test NIR spectroscopy for screening counterfeit products. The results showed that qualitative and quantitative NIR models of the generic drugs can be constructed, despite differences in formulation and physical properties of the tablets from the different manufacturers. In the case of the vitamin tablets, there is a high correlation between the spectra and the active ingredient content of the drug formulations. The differences in the active ingredients are significant enough to discriminate the tablets. Combining qualitative analysis with quantitative analysis further increases the effectiveness of NIR analysis. NIR spectroscopy offers an excellent opportunity for use as a screening technique to detect counterfeit samples.

Keywords: near infrared spectroscopy, screening counterfeit drugs, qualitative model, quantitative model, generic drug, vitamin tablet