A simple protocol for the characterization of fraudulent erectile dysfunction medicines using ion beam analytical techniques

Abstract

In this work we developed a simple and fast protocol based solely on ion beam analytical techniques for the analysis of erectile dysfunction medicines containing sildenafil and vardenafil as active ingredients. To that end, RBS (Rutherford Backscattering Spectrometry), PIXE (Particle-Induced X-ray Emission) and MeV-SIMS (Secondary Ion Mass Spectrometry) were employed in the analysis of sildenafil citrate (Viagra®), vardenafil hydrochloride (Levitra®) and tadalafil (Cialis®) among other medications. The RBS and PIXE techniques provide information on the concentrations of major and trace elements present in the tablets respectively, while the MeV-SIMS technique was used for the determination of the molecular profile of the samples. The protocol is based on the detection of sulfur present in the tablets through the PIXE technique, while its validation relies on the detection of the active ingredients with the MeV-SIMS technique.

The results confirm that the protocol is quite suitable for the discrimination of different sildenafil- and vardenafil-based medicines. On the other hand, this protocol cannot be used for the study of tadalafil-based medicines since no detectable element by PIXE is present in its active ingredient.