Identification of undeclared active pharmaceutical ingredients in counterfeit herbal medicines used as opioid substitution therapy

Adulteration of traditional herbal drugs with undeclared active pharmaceutical ingredients is a global problem with the increase in popularity of herbal-based medications. Many unprofessional herbal stores introduce herbal medicines as traditional formulations, but there are poor regulations for traditional herbal products' consistency and safety in Iran. The current study aimed to identify undeclared active pharmaceutical ingredients in traditional herbal medicines used as opioid substitution therapy. In this research study, systematic toxicological analysis was performed for the analysis of 80 traditional herbal medicine samples. Samples were prepared and analysed by gas chromatography/mass spectrometry (GC/MS) instrumentation. More than 96% of samples contained at least one pharmaceutical active ingredient. Diphenoxylate and tramadol were detected in 90% and 67% of samples respectively. Moreover, some other pharmaceutical ingredients such as acetaminophen, codeine, sertraline, and fluoxetine were found in the samples. Quantitative analysis of samples showed that capsules contained diphenoxylate and tramadol at concentrations of 1.4-4 mg/capsule and 67-150 mg/capsule respectively. Traditional herbal preparations are not regulated as medicines in Iran. Herbal drugs with undeclared active ingredients are potentially dangerous for consumers; therefore, serious safety concerns must be associated with their production, distribution and use.