Chemometrics and chromatographic fingerprints to discriminate and classify counterfeit medicines containing PDE-5 inhibitors

► Impurity profiles treated as fingerprints in counterfeit detection. ► 48 illegal and 9 genuine Viagra®, 44 illegal and 6 genuine Cialis®. ► 100% CCR for discrimination: genuine/counterfeit with kNN, SIMCA and LS-SVM. ► Best overall classification with LS-SVM and SIMCA.