title: Rapid detection and identification of counterfeit and [corrected] adulterated products of synthetic phosphodiesterase type-5 inhibitors with an atmospheric solids analysis probe.
abstract: The market success of the three approved synthetic phosphodiesterase type-5 (PDE-5) inhibitors for the treatment of erectile dysfunction has led to an explosion in counterfeit versions of these drugs. In parallel a large market has developed for herbal products claimed to be natural alternatives to these synthetic drugs. The herbal products are heavily advertised on the internet and are freely available to purchase without prescription. Furthermore, adulteration of these supposed natural medicines is a very common and serious phenomenon. Recent reports have shown that the adulteration has extended to the analogues of the three approved synthetic PDE-5 inhibitors. An Atmospheric Solids Analysis Probe (ASAP) was used for the direct analysis of the counterfeit pharmaceuticals and herbal products. Using the ASAP combined with time-of-flight mass spectrometry (TOF MS) it was possible to detect fraudulent counterfeit tablets. The physical appearance of the pills resembled the pills from the original manufacturer but contained the wrong active pharmaceutical ingredient (API). Detecting adulteration for five herbal supplements marketed as natural alternatives to PDE-5 inhibitors was also possible using the ASAP. Three types of adulteration were found in the five samples: adulteration with tadalafil or sildenafil, mixed adulteration (tadalafil and sildenafil), and adulteration with analogues of these drugs.
authors.affiliation: Waters Corporation, Milford, MA 01757, USA.
authors.forename: Marian
authors.initials: M
authors.lastname: Twohig
authors.forename: St John
authors.initials: SJ
authors.lastname: Skilton
authors.forename: Gordon
authors.initials: G
authors.lastname: Fujimoto
authors.forename: Nicholas
authors.initials: N
authors.lastname: Ellor
authors.forename: Robert S
authors.initials: RS
authors.lastname: Plumb
mesh_terms: D002243:Carbolines / Q000737:chemistry / Q000302:isolation & purification; D058110:Counterfeit Drugs / Q000737:chemistry / Q000302:isolation & purification*; D013058:Mass Spectrometry / Q000379:methods; D058986:Phosphodiesterase 5 Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D010879:Piperazines / Q000737:chemistry / Q000302:isolation & purification; D028321:Plant Preparations / Q000737:chemistry / Q000302:isolation & purification*; D011687:Purines / Q000737:chemistry / Q000302:isolation & purification; D000068677:Sildenafil Citrate; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013450:Sulfones / Q000737:chemistry / Q000302:isolation & purification; D000068581:Tadalafil; D013997:Time Factors
chemical_list: D002243:Carbolines; D058110:Counterfeit Drugs; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D028321:Plant Preparations; D011687:Purines; D013450:Sulfones; D000068581:Tadalafil; D000068677:Sildenafil Citrate