Analysis of Ephedrine and Illegal Adulterated Anorectics in Herbal Formulations for Weight Loss by LC-MS/MS

With the increasing prevalence of obesity, the use of herbal medicines for weight loss is widespread because they are believed to be safer and healthier than synthetic drugs. However, there are concerns about safety issues and potential side effects. To investigate the usage of ma-huang and the presence of pharmaceutical adulterants, we conducted an analysis of ephedrine and illegal adulterated anorectics in various herbal medicinal products, prescription drugs, and dietary herbal supplements for weight loss. A liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) method was developed and validated for the simultaneous determination of 9 weight loss compounds including ephedrine, phentermine, topiramate, sibutramine and their analogues. The validation results for selectivity, linearity, matrix effect, limits of detection (LOD) and limits of quantification (LOQ), intra- and inter-assay precision and accuracy were satisfactory. The ephedrine content in prescription medications ranged from 12.9 to 115.4 mg/day, and in herbal preparations from 5.0 to 39.8 mg/day. Undeclared anorectics were not detected in any of the 54 samples. Closer supervision of the inappropriate use of anorectics is necessary, along with regulations for the maximum intake of ephedrine in weight loss formulations.