The toxicological analysis of Cu, Mn and Zn as elemental impurities in pharmaceutical herbal products for teething available in pharmacies in Poland

The monitoring of elemental impurities (EIs) in pharmaceutical materials is often not adequately treated, although it is a very important topic because the directive ICH Q3D requires a wide range of elements, often at low concentrations, to be monitored. This article describes the quantitative toxicological analysis of copper, manganese and zinc as EIs in the pharmaceutical gels for teething containing herbs available in Poland. The levels of EIs were measured to evaluate whether the intake of these metals through the gels was within recommended levels. The flame absorption spectrometry (FAAS) following microwave induced digestion (concentrated nitric acid) was applied to determine the levels of Cu, Mn and Zn in the products. This article was motivated especially by the facts that: (i) herbs can be a potential source of EIs; (ii) Cu, Mn and Zn are essential trace elements in the infancy period; (iii) there is a general lack of data around the risk assessment associated with exposure to these EIs in this kind of pharmaceutical. Our safety assessment is based on triple approach including: (1) profile of EIs in gels; (2) the actual amount of EIs in the appropriate amount of gel applied with a single administration (one drop) and (3) the daily exposure of EIs in analysed teething pharmaceuticals due to the maximum daily dose. Our results show that all EI levels meet the standards of directive ICH Q3D. It can be concluded that all of the teething gels investigated, based on herbs, available in Polish pharmacies do not represents a health hazard to babies.