engleski

ANALYSIS OF UNDECLARED SYNTHETIC PHOSPHODIESTERASE-5 INHIBITORS IN DIETARY SUPPLEMENTS AND HERBAL MATRICES BY LC–ESI–MS/MS AND BY LC-TOF ON MARKET IN PERIOD 2012-2019

Erectile dysfunction (ED) is a condition in which man are unable to achieve or maintain an erection firm enough for satisfactory sexual intercourse. Synthetic phosphodiesterase type 5 (PDE-5) inhibitors are widely used for treatment of erectile dysfunction. There are four PDE5 inhibitors approved for treatment in Europe and the United States: avanafil, sildenafil, tadalafil and vardenafil. In order to protect the public from fraudulent practices, adequate methods for dietary monitoring should be enforced. This includes screening methods and strategies for the identification of new and unapproved compounds, while focusing on quantification of adulterants. The aim of this study was to investigate herbal dietary supplements sold on the Croatian market for the presence of PDE5 inhibitors and their analogues in period 2012-2019. In this study, dietary supplements and herbal matrices of different forms collected from the Croatian market (pharmacies and store) were analyzed by LC–ESI–MS/MS or by HPLC-TOF-MS. Methods have been validated in terms of specificity, precision, accuracy, detection and quantification limits, linearity, stability and recovery. Three different forms of blank samples, pills, capsules and honey were used in the validation process. Validation parameters meet all acceptance criteria. PDE5 inhibitors were analyzed in 94 samples by method LC–ESI–MS/MS 57 samples in the period 2012-2013, 37 samples in the period 2014-2016, and 35 samples were analyzed by HPLC-TOF-MS in the period 2017-2019, of which 11, 15 and 19 were positive, respectively. Using a more sophisticated technique and examination of unknown substances, an increase in positive samples was observed from 19%, 41% and 54% respectively. In the case of positive samples, sildenafil and tadalafil in tablet combination were most commonly detected. As a conclusion adulteration of supplements with PDE-5 inhibitors and their analogues is extremely dangerous for consumers due to the unknown efficacy and toxic effects and should be inspected.

PDE-5 inhibitors, analogues, herbal dietary supplements, High-Performance Liquid Chromatography (HPLC), time of flight mass spectrophotometer (TOF-MS

nije evidentirano