Legal requirements for the control of contaminants in herbal medicinal products

Abstract

Herbal medicinal products require a pre-marketing approval like all other medicinal products and have to prove their quality, safety and efficacy in order to guarantee optimum consumer and patient protection according to the European legislation. Taking into a consideration the natural origin and potential environmental influences, special emphasis is put on tests for contaminants such as heavy metals, pesticide residues, mycotoxins and microorganisms. For heavy metals, the European Pharmacopeia has set limits for lead, cadmium and mercury within the general monograph on herbal drugs. Similar rules are being developed for extracts. In this respect, a German industry's working group has collected a large amount of data on heavy metals occurring in herbal drugs. The respective data base has been evaluated and published [1]. For pesticide residues in plant material, the respective European Pharmacopoeia monograph sets limits for 70 substances. For further substances reference is made to Regulation (EC) 396/2005 on pesticide residues in food. For aflatoxins, specific limits exist for medicinal products which are comparable to the food area. With regard to microbiological purity of herbal medicinal products, the European Pharmacopoeia describes requirements for three different categories of these products as well as determination methods. Raw materials of herbal origin which are intended for use in food supplements have to fulfill the respective European legal requirements for the food area. Besides the above mentioned Regulation (EC) 396/2005 on pesticide residues, limits for further contaminants are described in Regulation (EC) 1881/2006, e.g. for mycotoxins or heavy metals. The Unites States Pharmacopoeia (USP) is currently developing specific rules on heavy metals in dietary supplements of botanical origin.