Detection and risk evaluation of counterfeit medicines based on physico-chemical properties: the fingerprint and chemometrics approach
27 May 2016
UAntwerp - Campus Drie Eiken - Building Q - promotiezaal - Universiteitsplein 1 - 2610 Antwerp (Wilrijk)
4:00 PM - 6:00 PM
Phd defence Deborah Custers - Department Pharmaceutical Sciences
Counterfeit medicines pose a global threat to public health. These products are not subjected to quality control and therefore their safety, efficacy and quality cannot be guaranteed. The types of medicines sold most as counterfeits in industrialized countries, and hence the subject of this thesis, are PDE-5 Inhibitors (treatment of erectile dysfunction) and weight loss products. High amounts of counterfeit pharmaceuticals enter the European market. Consequently, analytical techniques able to detect these kind of products and distinguish them from genuine medicines are indispensable.
Several techniques were tested for this purpose, including both spectroscopic and chromatographic techniques, which aimed at acquiring characteristic fingerprints for each sample. These fingerprints were subsequently analysed using chemometrics in order to construct diagnostic models and extract useful information. The acquired models aim at predicting the genuine or counterfeit nature of unknown samples.
It is demonstrated that fast and easy-to-use techniques, such as IR spectroscopy, are capable to discriminate between genuine and counterfeit medicines. In general, IR spectrometers are relatively cheap and user friendly, which renders them suitable for field work (e.g. initial analysis by customs officials). More complex techniques, such as liquid and gas chromatography, were also tested. Besides the aimed distinction, they also provide additional information useful to evaluate potential public health threats posed by counterfeits. For instance, it was shown that by using gas chromatographic fingerprinting present residual solvents could be detected and identified; liquid chromatographic fingerprinting proved useful for the detection and identification of forbidden synthetic substances.
In general, it can be concluded that fingerprinting proves to be a useful strategy for the screening of illegal pharmaceuticals. Based on the desired information, a suitable analytical technique can be selected. The information acquired by spectroscopic techniques is often very limited and therefore they usually only allow for the distinction between genuine and counterfeit medicines. On the contrary, chromatographic techniques not only distinguish genuine from counterfeit medicines, they also allow to evaluate each sample for its potential public health threat. In the future, this working strategy could potentially be expanded to other pharmacological classes of counterfeit medicines such as sleeping aids and pain killers.