Industry discussions are currently trying to address individual metal elements, with appropriate methods and appropriate safety-based
limits based on the literature. Comments from the Council of Responsible Nutrition, for example, argue that "irrespective
of the methodological approach, the absence of clearly defined criteria against which a given method may be assessed precludes
the identification of a suitable method. As yet, USP has not defined these criteria. Therefore, it is impossible to comment
on the methodology in a meaningful way" (3).
Adds Schoneker, "Overall, the concept of a flexible approach to a methodology is what industry would like to see. Most of
the people I've talked to, tend to agree with this as long as there is a clear mechanism for how it will get handled from
a regulatory compliance standpoint. That said, industry would like to see USP just use the four key metals during the initial
implementation of this concept so we can learn the appropriate approach that can be easily applied to other metals."
During the rest of 2009, the details related to USP ‹231› will undergo revision and strategies for what industry hopes will be a gradual, realistic implementation plan. "There
are two different intentions coming at this task," says Boyajian. "USP in the stimuli article seems to be trying to replace
the intention of the chapter, while industry as represented by the project team that I am on is saying there was not much
there, so adding four elements is already a significant improvement, a great start, and a huge cost increase from what is
there now. But I think it's a good thing that we're even discussing it, and it will help us all in the long run."
1. USP Ad Hoc Advisory Panel on Inorganic Impurities and Heavy Metals and USP Staff, "General Chapter on Inorganic Impurities:
Heavy Metals," stimuli to the revision process, Pharmacopeial Forum 34 (5), 1345–1348 (Sept.–Oct. 2008).
2. N.L. Lewen, "Revision Approaches to the Heavy Metals General Chapter" presented at the USP Annual Meeting, Kansas City,
3. A. Shao, CRN comment letter, Dec. 15, 2008,