Experts Address Chondroitin Testing In Wake Of ConsumerLab Report
Experts see educational opportunity in ConsumerLab joint supplement report finding chondroitin levels in 7 of 11 products failed to meet label claims. Analytical scientists, industry execs not surprised by report, citing firms inappropriate testing. Experts stress use of AOAC enzymatic HPLC method, update its status on becoming official method.
Results of a recent ConsumerLab.com report on joint supplements that found 7 out of 11 tested products contained less chondroitin than stated on the label did not surprise experts in the industry.

Additionally, experts appear to agree, the fact that a product contained little or no chondroitin does not mean the manufacturer neglected to perform analytical testing.

Out of seven products ConsumerLab failed, a “maximum strength” chondroitin-only supplement contained no chondroitin; three supplements had 1 percent to 8 percent of the claimed chondroitin, and three more contained between 51 percent and 75 percent of the promised chondroitin. Additionally, ConsumerLab failed an eighth supplement “because it would not break apart properly.”

In sum, ConsumerLab tested 34 products; these included glucosamine and chondroitin combination products (with and without MSM), chondroitin-only products, glucosamine-only products and MSM-only products. Five of the tested products – and two of the failed products – were for pets.

“Why are there so many chondroitin products with quality problems?” ConsumerLab asks in its April 13 report. “Some manufacturers may rely [on] nonspecific tests, such as the ‘CPC (cetyl pyridinium chloride) titration method’ or ‘size-exclusion chromatography method’ when evaluating chondroitin,” the firm replies.

Industry experts interviewed by “The Tan Sheet” agree.

“It’s really become clear that people are confused as to what method they should be following, when they should be switching to another method [and] what an ‘official method’ means,” Blaze Science Industries CEO and Technical Director Jana Hildreth said.

Currently, there is no stand-alone “official method” to both identify chondroitin sulfate and quantify the amount of the ingredient in a wide variety of matrices, experts said.

However, an enzymatic HPLC method is swiftly approaching this status, they agreed. The method was selected from amongst a number of methods by a 2003 AOAC International Dietary Supplements Task Group Expert Review Panel.

It is the only method that has been validated for a finished product, as well as a wide range of matrices, Hildreth said.

The enzymatic method tests for chondroitin sulfate A and chondroitin sulfate C, she added. Potential interferences such as heparin and dermatan sulfate (chondroitin sulfate B) will not show up in the test, Hildreth added.

Since 2003, the method has passed single-lab validation. The next step is a collaborative study of the method involving eight to 10 labs, Hildreth said. Assuming it passes the collaborative review, it will be slated to become an “official method.”

“The only method at this point that can function as a stand-alone method is this enzymatic method. Now the confusion people have is, ‘Well, we don’t want to switch because it’s not an official method,’” Hildreth said. “But if it’s already passed single-lab validation ... you can be pretty confident that this method is going to be reproducible,” she added.

Furthermore, “If there’s not an official method, FDA or other people will realize that you take what has the most science behind it, and at this point this single-lab validation already fits that bill,” she said.

An FDA staff member told “The Tan Sheet,” “The agency has not considered what would constitute an acceptable method for purposes of determining chondroitin content of dietary supplements.”

However, in general, the agency gives a certain degree of flexibility to recommendations having to do with such things as testing methods in order not to stifle industry innovation, a spokesperson added. This kind of thinking can be seen, for example, in the agency’s “Good Manufacturing Practices for the 21st Century Initiative” (“The Tan Sheet” July 3, 2006, p. 6).

The collaborative study of the enzymatic method should start in about a month, according to Tampa Bay Analytical Research President Mark Roman. Roman is also a co-study director for the collaborative study.

Participating in the inter-lab validation is the Spanish firm Bioiberica, which supplied the chondroitin sulfate for NIH’s Glucosamine/Chondroitin Arthritis Intervention Trial. According to Jordi Ruiz, Ph.D., the firm received the samples and final methodology April 20.

“If things go smoothly, roughly three months from now the manuscript will be submitted for publication,” Roman said.

However, not all firms appear eager to adopt the enzymatic HPLC method.

“We have learned that at least one of the companies with a deficient product was relying on a nonspecific method, the [size-exclusion chromatography] method, for certification of its chondroitin material,” ConsumerLab President Tod Cooperman said in an e-mail.

“Apparently, this company is now trying to mislead consumers into believing that this is the most appropriate way to quantify chondroitin, which it is not. We are making sure that consumers know better.”

As ConsumerLab notes in the report, another nonspecific test some firms use is CPC titration. CPC titration is only one test among many required by the United States Pharmacopeia method, Roman said. If a firm is not running the rest of the tests in the suite, “they really have no idea whether or not they have chondroitin sulfate in there.”

Additionally, the USP method is not for testing finished products, Hildreth said.

ConsumerLab used the enzymatic HPLC method to test the finished products, according to the report. “We chose it because it is specific and has been validated,” Cooperman wrote. Additionally, “for every product that failed this test, we also had a second lab run the [capillary electrophoresis] method as confirmation,” he added.

When a firm employs a non-specific method like CPC titration as a stand alone method, the company “may actually be doing analytical testing, and they may even think they’re doing the proper testing. But then somebody like ConsumerLab comes along and they run either the entire USP monograph or they run the enzymatic method and it turns out, well, the stuff really isn’t chondroitin sulfate,” Roman said.

“If you want our opinion, what has been seen in the ConsumerLab report is something that is not strange for us,” Bioiberica Joint Care Manager Joan Bassa said.

Bioiberica has been testing different products marketed as containing chondroitin sulfate on an ongoing basis. “We have arrived at the same conclusion as ConsumerLab: There are problems in the U.S. market,” Bassa said.

“The problem is these types of companies could effect the consumer. We don’t want the consumer to think that chondroitin doesn’t work,” he said, noting the product will not work if the active ingredient is absent or insufficiently dosed.

However, “there are very good companies in the U.S. market using the correct dosage and [putting] a very good product in the market,” Bassa said.

“I have been very impressed that all of the major players have very good [quality control] for chondroitin right now, and it’s been a progressive effort industry-wide to do the right thing,” Luke R. Bucci, Ph.D., Schiff Nutrition International’s vice president of research, said.

Schiff uses both the enzymatic HPLC method and the CE method, Bucci said.

All of Schiff’s products tested by ConsumerLab passed the review. Nutramax Laboratories’ Cosamin DS, which uses chondroitin sulfate supplied by Bioiberica, also passed the ConsumerLab test.

Enzymatic HPLC is expensive and is “not an easy method to run,” Hildreth acknowledged. If a firm gets to a point where their “need is not to determine identity, they should use their discretion as to what is the goal of their analysis and may not have to always follow these methods,” she said.

“If they come up with something else that’s better for routine type of testing,” the firm can use that method, Hildreth said. However, the firm should continue testing with the enzymatic method to make sure the source has not changed, she stressed.

“Good science is the winning thing,” Hildreth said. “If people are wanting to know do they really have chondroitin and not try to defend themselves after somebody’s told them they don’t, this is really the only method I have seen to date and is verified by an expert review panel that can properly qualify materials.” – Katia Fowler (k.fowler@elsevier.com)




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