Determination of Common Pharmaceutical Adulterants in Herbal Medicinal Products Used in the Treatment of Opioid Addiction

Background: Opioid addiction is a serious and growing global concern. Recently, herbal medicine has been popular for the treatment of opioid abusers worldwide. Unfortunately, the adulteration of herbal remedies with undeclared synthetic pharmaceuticals has been reported. In Iran, there are few reports on the adulteration of herbal remedies by synthetic pharmaceuticals sold as opioid addiction treatment. The aim of this study was to analyze herbal products used in opioid addiction treatment for the identification of synthetic pharmaceuticals as adulterants in the remedies.Methods: Forty commonlyused handmade herbal products for the treatment of opioid addiction were collected from herbal shops in Kermanshah (western area of Iran). After organoleptic examinations, the samples were prepared and analyzed by highperformance liquid chromatography and gas chromatographymass spectrometry for detecting probable synthetic pharmaceutical adulterants.Results: The chromatographic analysis of the samples showed that 90% of the products had at least one undeclared pharmaceutical ingredient as an adulterant. The majority of the samples (n=19, 47.5%) had only one undeclared pharmaceutical. Diphenoxylate (n=24, 39.3%), tramadol (n=16, 26.2), methadone (n=8, 13.2%), and the combination of these drugs were reported as common adulterants. We detected the presence of buprenorphine and sildenafil as adulterating agents in the herbal formulations for the first time.Conclusion: According to the presence of undeclared synthetic pharmaceuticals in opioid addiction herbal products, as well as their threats to public health, awareness, in this case, is necessary.