The identification of rimonabant polymorphs, sibutramine and analogues of both in counterfeit Acomplia bought on the internet.

Acomplia was ordered over the internet resulting in the delivery of counterfeit Acomplia and imitation products. The tablets were analyzed for the presence of rimonabant. Using LC-DAD-MSn the presence of effective quantities of rimonabant was confirmed in samples A-D. Samples A and D also contained traces of the rimonabant analogue NIDA-41020. Furthermore, NIR spectroscopy on the tablets indicated the presence of an unapproved rimonabant polymorph in samples C and D which was confirmed by Raman spectroscopy and X-ray diffraction (XRD). In sample E a low dose of sibutramine was found as well traces of N-desmethylsibutramine and bis-N-desmethylsibutramine. Rimonabant was withdrawn from the market because of serious adverse events and lack of efficacy. The availability of poor quality products with rimonabant, impurities and unapproved polymorphs is worrying. Suspect weight-loss medicines should be screened for the presence of novel analogues.