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Elemental Impurities

USP Announces New Elemental Impurities Standards Are Available for Public Comment; Comments Due April 15, 2010

USP is proposing three new General Chapters on Elemental Impurities Limits, Methods, and Dietary Supplements Metals Limits in the January-February issue of Pharmacopeial Forum (PF 36(1)). Other related information also will appear in PF 36(1), including a draft General Notices statement about the applicability of the standard to all monographs and two Stimuli articles outlining the rationale for the revisions and the comments received from an original Stimuli article and Workshop. The revisions focus on two areas of work:

• Updating the methodology used to test for elemental impurities in drugs and dietary supplements to include procedures that rely on modern analytical technology; and
• Setting limits for acceptable levels of metal impurities (including, but not limited to, lead, mercury, arsenic, and cadmium) in drugs and dietary supplements.

The USP Metal Impurities Advisory Panel, which reports to the USP General Chapters Expert Committee, worked with USP staff and stakeholders to assess methodologies and limits that provide greater patient/consumer protection and can reasonably be deployed across industry laboratories. The limits for exposure are toxicologically based and developed by an expert consensus process to provide quality standards that reflect consensus views about potential health/toxicity concerns.

These new approaches are intended to replace the existing methods in General Chapter <231> Heavy Metals.

Revisions Targeted for Pharmacopeial Forum 36(1) January-February 2010

• <232> Elemental Impurities - Limits  (59KB)
• <233> Elemental Impurities - Procedures  (801KB)
• <2232> Elemental Contaminants in Dietary Supplements  (502KB)
• Stimuli article Elemental Impurities – Information   (93KB)
• Stimuli article Elemental Impurities – Comments and Responses  (67KB)

Stakeholders may provide comments on these standards prior to the January release date of PF 36(1). Send comments to Kahkashan Zaidi, Ph.D., Senior Scientific Liaison, General Chapters, Division of Standards Development. (). Comments are due by April 15, 2010.

Frequently Asked Questions

• FAQs about USP's Proposed Standards for Elemental Impurities

Background Documents

• The Digest of Comments Received on the Stimuli Article "General Chapter on Inorganic Impurities: Heavy Metals" Published in Pharmacopeial Forum 34(5)  (174KB)
• The USP Advisory Panel on Metal Impurities "Draft Metals and Limits Table"  (14KB)
• Summary of USP Heavy Metals Testing Methodologies Workshop held August 26-27, 2008  (22KB)

Workshop on Metals in Pharmaceuticals and Dietary Supplements (April 28–29, 2009)

• General Presentation  (319KB)
• Final Summary Session  (197KB)

Reference Standards

USP intends to develop official USP Reference Standards in support of the revisions for the General Chapter on Metal Impurities. These new USP Reference Standards will provide high quality reference materials designed to help demonstrate compliance with the new chapter on metal impurities.

As the General Chapter evolves through the revision process, the type and number of USP Reference Standards will also need to be developed in USP's Analytical Research and Development laboratory. If you would like to receive email notifications when these new, first time Reference Standards become available, sign up for USP's Reference Standards Release Notification Program. Since there currently is no official USP Reference Standard name in the "Name of Reference Standard(s)" field please type "Metal Impurities".

Download the entire USP Reference Standards Catalog.

USP's Compendial Updates

To keep informed about any Revision Bulletin to General Chapter <231> Heavy Metals, sign up for USP's free Compendial Updates email service.

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Contacts

• Monographs: Kahkashan Zaidi ( or 301–816–8269)
• Media: Laura Provan ( or 301–816–8268)
• Reference Standards Technical Support: RS Technical Service ( or 301–816–8129)
• Reference Standards Ordering: USP Customer Service ( or 800–227–8772)