A case of medicine in disguise: motion sickness patches sold as medical devices containing active pharmaceutical substances.

Abstract

A case study is reported on anti-motion sickness transdermal patches sold in the Internet, claiming to contain only natural ingredients but, actually, containing undeclared medicinal active substances. The visual inspection of the samples evidenced many inconsistencies in secondary and primary packaging, missing of various legal information and a non-compliant "CE" mark. The qualitative analysis was performed by liquid chromatography - high resolution mass spectrometry and the quantitative by liquid chromatography with diode array detector. The analyses evidenced the presence of the antihistaminic drug Diphenhydramine and of other active substances (Capsaicin, a transdermal absorption enhancer, and Diclofenac in traces, probably a contaminant from other productions of the same plant). Moreover, the presence of several trace elements, including those potentially toxic to humans, was assessed by ICP-MS analysis. The case discussed is a new case of "medicines in disguise" never reported in literature, and shows the presence of tangible risks for public health.