oa A comprehensive UPLC-MS(/MS) based approach for screening and confirmation of illegally added erectile dysfunction (ED) drugs in natural health products

The adulteration of herbal/dietary supplements with erectile dysfunction (ED) drugs and their analogues is reported worldwide and is an increasing problem. The sale of so-called 100%, ’all-natural’ products has become a highly profitable business for online pharmacies, however these products can pose a serious threat to consumers owing to the undisclosed presence of approved/prescription drugs or the unknown safety and toxicity profile of unapproved ED drugs. The Drug QC Laboratory, Qatar, has been involved in the testing of adulterated and counterfeit products for a number of years. A simple and rapid UPLC-MS/MS procedure for the analysis of 42 synthetic ED compounds in herbal supplements is presented. A spectral library for the compounds and their analogues was generated from reference standards for automated routine analysis. Full scan MS analysis was performed simultaneously in both positive and in high energy negative ESI modes; In addition a MS/MS method was developed for confirmation and quantification of compounds. The method was applied to 87 suspected dietary products which were received to our laboratory. Twenty three were found to be adulterated: 11 with sildenafil, four with thiodimethylsildenafil/thiosildenafil, two with dapoxetine and five contained a combination of verdenafil, tadalafil, aminotadalafil, hydroxthiohomo sildenafil. One sample contained unknown analogue named as propoxyphenyl thiohomosildenafil. Developed method is a novel screening method that is suitable for both the detection of known and unknown ED drugs and their analogues. This is the first description of a single analytical method with this capability.