Review: Quality of herbal medicinal products: State of the art of purity assessment

Background The European Pharmacopoeia as well as further legal provisions contain rules for the assessment of potential residues and contaminants in herbal substances and preparations used for the production of herbal medicinal products, e.g. for the assessment of pesticide residues, heavy metals and other elemental impurities, mycotoxins and microorganisms. As a potential contamination caused by weeds, the occurrence of pyrrolizidine alkaloids is being discussed for several years which lead to measures of health authorities limiting the PA content in herbal medicinal products and to measures of industry consisting of reducing the probability of PA occurrence in medicinal plants and the respective products. Conclusion In this context and with regard to all kinds of potential residues or contaminants, collection and evaluation of data from daily analytical practice of manufacturers and suppliers is useful for the assessment of the situation and the definition of testing strategies.