A recently approved method for monitoring the purity of the popular dietary supplement ingredient chondroitin sulfate is beginning to see increased use, according to experts.

It’s a major step forward for the industry, said Darryl Sullivan, director of scientific and regulatory affairs at Covance Laboratories, because chondroitin manufacturers have for some time been plagued by unscrupulous ingredient suppliers selling adulterated products. The adulterants they contained (such as carrageenan and alginates) fooled existing tests, “even though the products were far from being good-quality chondroitin,” Mr. Sullivan said. “It was a common problem because high-quality chondroitin sulfate is a very expensive ingredient, so it has a high potential for being adulterated.”

Technically speaking, the new method isn’t “new”—it dates all the way back to a research paper published in 2007. But it was only last fall when it was reviewed by an expert panel convened by AOAC International that it was able to become the go-to method for measuring chondroitin sulfate content in dietary supplements and their ingredients.

Standards Development
AOAC is a 130-year-old non-profit organization devoted to reviewing analytical methods used in FDA-regulated industries and designating those that pass muster as AOAC-approved Official Methods of Analysis. Over the years, the AOAC stamp of approval has become so widely respected that AOAC official methods have become the gold standards for measuring their analytes, widely accepted by industry and regulators.

Currently, AOAC is working under contract with the Office of Dietary Supplements (ODS) at the National Institutes of Health to produce a list of what will eventually be a total of 25 “priority ingredients” for which standards and reliable methods are most needed and to go through the process of evaluating candidate methods for each of them. It begins with stakeholder panels in which industry, regulators, consumers and academic scientists work together to determine what standards an official method needs to meet; then they put out a call for methods to be evaluated against these standards by an expert review panel. (For further reading, see “Ingredient Authentication in the Lab,” in Nutraceuticals World’s January/February 2016 issue.)

Chondroitin Spotlight
Chondroitin is one of the first of these ingredients for which an official method has been designated. It’s an important test case for how well this process will work because not only has it been prone to economic adulteration, but it’s also one of the world’s most popular supplements, often mixed with glucosamine and MSM to support joint health and function. Even four-time Superbowl champion Joe Montana has lent his name as spokesman for one such product. “It is a very important ingredient to the industry,” Mr. Sullivan said.

And, he added, the new method’s designation as official has already been “very impactful” for the industry. The value of that designation, he noted, stems from the respect that AOAC official methods carry among scientists and regulators—a respect that allows the industry to use it with confidence that it indeed produces accurate results.

“Knowledgeable people trust this method,” said David Ji, laboratory director for Analytical Laboratories in Anaheim, Inc.

But it’s more than just scientific accuracy. Being able to use AOAC official methods also reduces regulatory burdens, Mr. Sullivan said, because there is no need to prove in an audit that the company’s test methods are valid. “An official method from AOAC stands on its own to a GMP auditor,” he said. “It doesn’t require documentation.”

Additionally, having such a method available increases the faith of everyone from the manufacturer to the consumer that the product is what it says it is. “We now have a much better security wall with our supply chain,” Mr. Sullivan said.

Already, use of the newly approved method is increasing, even though there has been less than a year for word of its approval to filter out to industry.

It’s a rare day, said Mr. Ji, when his team doesn’t use the test at least once. On average, he estimated, his team uses it to process about 10 samples a day, and in recent months he’s been receiving “more and more” samples to be tested with it, ranging from raw materials to finished products. In addition to traditional dietary supplements, his lab gets samples of foods, drinks and even pet foods.

And while Mr. Ji probably conducts more of these tests than most (he was one of the scientists who first developed the method), he’s not the only one. Mr. Sullivan said that his own lab, in Madison, WI, is starting to see several samples a week submitted for the new analysis.

It helps that it doesn’t require exotic equipment of the type found only in academic laboratories, he noted. “Any laboratory that’s used to doing HPLC and enzyme-preparation analyses shouldn’t have any problem producing high-quality results.” Furthermore, he said the method has already helped clean up the chondroitin supply chain. Client confidentiality prevents him from commenting on specific cases, but he has already seen “probably four or five examples” of adulterants discovered by it that might otherwise have slipped through. That said, the benefits are merely beginning to be realized.

That’s partly because it takes time for the news to work its way to an ever-larger audience. But also, the official method status comes under a procedure that AOAC calls “First Action” official approval—which, not surprisingly, means there is something called “Final Action” yet to come.

Phases of Official Methods Status
First Action methods are every bit as official as Final Action methods. Both types get published in AOAC’s annual compendium, Official Methods of Analysis and the Journal of AOAC INTERNATIONAL. First Action approval, however, is an expedited process. It has the advantage of being able to produce official methods very quickly (the record is under a fortnight, when ecoterrorists threatened to contaminate infant formula with a rodenticide for which there was no official test). But the “first” in “First Action” means exactly that: there is an expectation that such methods may need additional tweaking before they are finalized.

That tweaking, noted Steven Dentali, PhD, a pharmacognosist and research fellow in botanical development at global nutrition company Herbalife, typically takes a couple of years, during which labs use the method and report back to AOAC’s experts on whether there are details that might need to be improved. “It’s with that feedback that a method can reach final action,” he said. And once that happens, the official method has nearly universal applicability. “If the method is followed, different labs and different analysts should get the same result—something that is critical in situations of economic adulteration.”

Already several such tweaks have been made for the chondroitin method, although Jana Hildreth, director of technology and scientific affairs of Synutra Pure, a leading chondroitin supplier, calls them “minimal changes” that should not deter people from using the method.

Mr. Ji agreed. The method works by using an enzyme to cleave chondroitin into component disaccharides that can be used as fingerprints of how much chondroitin was originally present by extracting the disaccharides from the enzyme mix and putting them through an HPLC column that separates them for UV detection. Ms. Hildreth’s “tweaking,” takes the form of optimizing the technical conditions (such as the type of column being used and the temperature at which it is to be held) in order to separate the disaccharides more effectively.

There are also changes in how the sample is dried in order to prevent water weight from affecting the test results, plus a test to verify the activity level of the enzymes used to digest the chondroitin into its component disaccharides (a potential issue because different suppliers might produce enzymes with different activity levels). But in the grand scheme of things, these are pretty minor—things that Ms. Hildreth referred to as “optimizations”—exactly the type of things that distinguish First Action methods from Final Action methods.

Reference Materials
Slightly more significant is the need for better reference materials for calibrating the test. At the moment, there are two problems. One is that the method currently uses the relevant disaccharides as its reference standards. That’s a potential difficulty, said Ms. Hildreth, because all supply houses get this chemical from the same manufacturer, and it is a very small part of that manufacturer’s business. So when one supply house is out of stock, odds are that everyone is—producing the prospect of a serious bottleneck. “You can’t run your method if you have no reference standard,” she noted.

She and Mr. Ji added that even if the supply of disaccharides were guaranteed, it would be even better to calibrate the method with a reference standard of pure chondroitin sulfate. At the moment, however, that’s not available: the current standard, Mr. Ji said, is only 85% pure.

But that too is just a short-term technical issue. The needed reference materials are already being developed by the National Institute of Standards and Technology (a division of the U.S. Department of Commerce). The goal, according to Mr. Ji, is to obtain a standard that is 95% pure—10% better than the best currently available. And while that will require some recalibration, Ms. Hildreth noted that even with current sub-optimal reference materials, the new method is dramatically better than the old one. The changes really are nothing more than the type of tweaks and calibrations that turn “excellent” into “even better.”

Dr. Dentali noted that all of this is what makes AOAC official methods so important for industry, whether the ingredient of interest is chondroitin or something else. Without such well-vetted tests, he said, it’s impossible to tell if any given ingredient, including others currently working their way through the ODS/AOAC process, really are what they claim to be—or, for that matter, don’t contain potentially dangerous contaminants. (For further reading see, “Six More Dietary Ingredients Picked for Analytical Identification,” in Nutraceuticals World’s March 2016 issue.) 

AOAC-approved methods, according to Dr. Dentali, “provide a reference point for both industry and regulators. If you don’t have a reliable way to measure something”—his voice drops off with the verbal equivalent of a shrug—“you can’t know what it is.”

Meanwhile, one of the next analytical issues up for consideration is ethanol in kombucha, an effervescent, fermented sweet tea sometimes sold in bottles and sometimes made at home from packets of yeast and bacteria. Unlike chondroitin, there’s no concern about adulteration; the issue here is taxes. “If it contains over 0.5% alcohol, it’s an alcoholic beverage and there are tax implications,” Dr. Dentali said. Methods proposals can be submitted to AOAC (at no fee) until July 15, 2016.