Rapid Detection and identification of Synthetic Phosphodiesterase Type-5 Inhibitors in Counterfeit and Adulterated Products using the Atmospheric Solids Analysis Probe

The adulteration of herbal dietary supplements with synthetic pharmaceuticals has been recognized as a growing problem internationally, with the number of detected cases rising every year. This has created a demand for high throughput analysis techniques. In recent years novel ambient desorption ionisation techniques for surface analysis of solid and liquid samples with subsequent MS detection have been reported [1,2,3]. Here we examine the utility of the Atmospheric Pressure Solids Analysis Probe (ASAP) for the rapid determination of synthetic phosphodiesterase type-5 inhibitors (PDE5) in counterfeit tablet samples and adulterated herbal supplements. Authentic brand sildenafil citrate, vardenafil hydrochloride and tadalafil were obtained from reputable pharmaceutical wholesalers. Imitation „brand“ samples of these drugs were obtained from internet pharmacies. Five Herbal dietary supplements (HDS) available freely without prescription were also purchased on-line. Samples were analyzed by ASAP with high resolution MS. The instrument was operated in combined ESI/APCI mode. The principal active component in 13 tablet samples was identified by ASAP in less than 20 minutes. Sample extraction was not necessary and chromatographic separation was not required to determine if the sample contained what it claimed to. Though the appearance of the imitation tablets conformed to the appearance of the genuine medicine, results from ASAP with Time-of-Flight (TOF) MS detection showed that the vardenafil and tadalafil pills contained the wrong active pharmaceutical ingredient (API). All herbal supplements purchased were found to be adulterated, containing either Sildenafil and/or Tadalafil or analogues of these drugs, none of which was declared on the box or enclosed information. References: [1] Takats Z, Wiseman JM, et al. (2004) Science, 306: 471. [2] Cody R, Laramee J, et al. (2005) Anal Chem, 77: 2297. [3] McEwen CN, McKay RG, et al. (2005) Anal Chem, 77: 7826.