GABRIEL LUCIAN RADU, ANCA MIHAELA POPESCU, CAMELIA GEORGIANA NICULAE, ADINA ELENA RADUCANU, TATIANA ONISEI IDENTIFICATION BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY OF HERBAL FOOD SUPPLEMENTS ADULTERATED WITH PDE-5 INHIBITORS
The aim of this study is to develop a new, easy and efficient analitical method, in order to perform the screening of herbal food supplements for improving the quality of sexual life, suspected to be adulterated with phosphodiesterase-5 inhibitors (PDE-5 inhibitors). PDE-5 inhibitors are substances such as: sildenafil (Viagra®), tadalafil (Cialis®), vardenafil (Levitra®) and more recently, avanafil (Stendra™), used in the treatment of erectile disfunctions. In recent years, there have been many cases reported where food supplements for enhancing sexual performance, promoted as „100% natural”, turned out to be adulterated with this type of substances or their analogues. On the label of this sort of products such substances are not mentioned, and thus, serious health problems can be caused to consumers, because PDE-5 inhibitors interact with nitrates based drugs. For this reason, a number of 26 herbal supplements found on the Romanian market were analysed using ion-spray liquid chromatography/tandem mass spectrometry (LC-MS/MS). These supplements have originated from various countries, such as: China, Canada, Japan, United Kingdom, USA, France, India and Romania. The identification of these pharmaceutically active substances was performed by selecting the specific molecular ions for each compound: sildenafil (parent ion 475.2, product ions: 311.2, 299.1, 255.1), tadalafil (parent ion 390.2, product ions: 268, 169, 135) and vardenafil (parent ion 489.2, product ions: 312.1, 299, 284). As a result of the screening of these products, 18 of them were identified having PDE-5 inhibitors in their composition, which means that 69% of analysed herbal food supplements, legally entered and marketed on the Romanian market, are adulterated.