The Level of Cadmium Impurities in Traditional Herbal Medicinal Products with Plantago lanceolata L., folium (Ribwort Plantain Leaves) Available in Polish Pharmacies — Comprehensive Toxicological Risk Assessment Including Regulatory Point of View and ICH Q3D Elemental Impurities Guideline

Plantago lanceolata L., folium (ribwort plantain) is an active pharmaceutical ingredient in traditional herbal medicinal products (THMP) available in pharmacies as a demulcent for the symptomatic treatment of oral or pharyngeal irritations and associated dry cough. This kind of THMP is widely applied among the European population; however, recently, voices have been heard in the public about alleged cadmium impurities. The idea of our study was a comprehensive risk assessment of the Cd impurity exposure and its effect on human health. Our assessment strategy was based on regulatory aspects (raw results versus limits set by FAO/WHO for herbal medicines) and toxicological risk assessment approach based on ICH Q3D guideline for elemental impurities in final pharmaceutical products. The cadmium was determined by electrothermal atomization atomic absorption spectrometry based on our previously described methodology. Obtained results show that all analysed THMP with P. lanceolata L., folium available in the Polish pharmacies contain cadmium impurities, but at a very low level (ranged 0.73 – 20.6 μg/L). The content of Cd in a single dose (ng/single dose) is also very low and is not a threat to patients. The estimated maximum daily exposure (ng/day) of Cd based on the ‘worst-case scenario’ (maximum concentrations by oral administration) meets the standards of ICH Q3D guideline (all results were below oral permitted daily exposure; PDE for Cd, i.e. < 5.0 µg/day). It can be concluded that all analysed samples of THMP with P. lanceolata L., folium should not represent any health hazard to the patients due to cadmium levels. To the best of our knowledge, this is the first study about Cd impurity level in THMP with P. lanceolata L., folium (ribwort plantain leaves) available in European pharmacies.