US EPA

8168176 

Journal Article 

General chapter on inorganic impurities: Heavy metals 

Zaidi, K 

2008 

34 

5 

1345-1348 

English 

In the ICH Q3A Impurities in Drug Substances guidance, impurities are classified as organic, inorganic, and residual solvents. Within the inorganic impurities classification, the metals listed in Table 1 are important to control in food, dietary supplements, and drug articles. Many toxic metal impurities found in pharmaceutical articles have been controlled for years by application of the Heavy Metals test described in USP-NF General Chapter Heavy Metals (231). However, the procedures and the methods contained in (231) lack the sensitivity, specificity, and recovery to monitor properly the levels of these metals. A number of additional chapters for the control of specific metals and other inorganic impurities are contained in USP-NF. This Stimuli article proposes a new USP General Chapter for the control of inorganic impurities in drug and dietary supplement articles intended for use in humans. For the purposes of this article, inorganic impurity, metal, and element all refer to those elements listed in Table 1. The proposed new General Chapter recommends procedures that rely on modern analytical technology and includes limits that are based on toxicity and exposure levels for the selected metals. The new General Chapter also introduces a performance-based approach for the selection of the appropriate technology. This chapter is proposed to replace (231) and may impact other General Chapters that control metals. © 2008 The United States Pharmacopeial Convention, Inc. All Rights Reserved.