The use of microtomographic imaging in the identification of counterfeit medicines

The practice of drug counterfeiting is an important challenge due to the extremely rapid growth rate of this disturbing trend and its immense potential harmfulness. According to WHO even 10% of counterfeit medicines can be exact copies of genuine medicines: they have exactly the same quantitative and qualitative composition in terms of both API and excipients. Thus, the identification of such drugs using chemical analysis methods can be very difficult or even impossible. The aim of this study was to verify the effectiveness of using computed microtomography in the identification of counterfeit medicines. The General Electric v|tome|x s microtomography system was used in the study. The recorded microtomographic scans were subjected to analysis and image processing. The following parameters of image analysis and processing were identified: mean brightness, homogeneity, contrast, quadratic tree decomposition. The original and falsified 100-mg Viagra® tablets (Pfizer) were compared. 8 original Viagra® tablets (hereinafter referred to as T) and 8 falsified tablets (hereinafter referred to as F1-F8) were tested. The range of variation for the genuine medicines against fake products was: brightness: 90.9-117.1 vs 33.8, 50.1, homogeneity: 0.84-0.92 vs 0.94-1.01 and quadratic tree decomposition for the 1 × 1 mask: 55768-58792 vs 0-439. The proposed method of microtomographic image analysis and processing enables to identify solid dosage forms, including those that are an accurate chemical copy, with high sensitivity and specificity, 94.5% and 97%, respectively. The advantage of the μCT method is its high efficiency and speed, whereas the disadvantages include the possibility of using only solid dosage forms and high equipment costs.