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Is USP 231 showing its age? Why a 100-year-old standard is going to be obsolete

Chemical Testing

A hundred years is an impressive age … for a tree, a bottle of wine, an historic building, a business or a person. That number is not so great, however, when you’re talking about scientific testing methods. Science and technology are constantly advancing, and a test methodology first implemented a century ago isn’t likely to have what it takes to accurately perform today. That’s the driving premise behind the U.S. Pharmacopeial Convention’s decision to revise its proposed standards for elemental impurities (EI) – commonly referred to as USP 231.

Think of the United States Pharmacopeia and National Formulary (USP-NF) as the Bible of drug ingredients in the U.S. Basically, the tome describes what goes into a medication, how it’s prepared and dosage amounts, plus it sets standards for an array of tests that all address the identity, strength, quality, purity, packaging and labeling for drugs, dosage forms and other therapeutic products such as dietary supplements. Although the USP itself isn’t involved in enforcing the standards set out in the USP-NF, federal regulations typically refer to USP standards.

The USP-NF is a compendium of two documents, both of which were first compiled and published in the 1800s. And therein lies the problem — the USP is now faced with updating some very old standards to accommodate modern-day applications and technologies. It’s doing this by working on replacement standards for USP 231. Originally, the changes were going to take effect in December 2015, but earlier this year, the USP announced a new target date of Jan. 1, 2018.[1]

According to the USP, “the test methodology currently described in the USP–NF, was first introduced more than 100 years ago. The test can be difficult to conduct, and can fail to detect some important elementals such as mercury at toxicologically relevant levels.”[2] In order to incorporate “modern analytical technology” into its recommended methodology for EI testing, and set acceptable limits for EI in drugs and dietary supplements, USP is in the process of revising USP 231, the section of its code that governs testing for heavy metals.

In fact, the current section and standards are so out of date that the USP is proposing to replace one chapter/set of standards with three: 232, which will deal with EI limits; 233 addressing EI procedures, and 2232 to address elemental contaminants in dietary supplements.

Although this may all sound a bit dry, the Polymer Solutions team — and many of our clients — is following these proposed changes closely. The analytical technologies that will be incorporated into the new standards are ones that we’ve been offering all along, such as Inductively Coupled Plasma Analysis (ICP) Spectroscopy and X-Ray Flourescence (XRF) Spectroscopy.

The presence of heavy metals and other impurities in products and packaging are of vital interest to manufacturers and consumers alike. While the Polymer Solutions team admires longevity, when it comes to scientific methodology, there’s a lot to be said for bringing current standards into the 21st century!