“FDA has made it clear in the regulations that their preferred unit of measure would be a metric of weight – a gram or a milligram – and that, for probiotics, does not provide the consumer with the information they would need to make an educated choice,” Smith, senior manager of scientific and regulatory affairs at DuPont, told us at the recent SupplySide West show in Las Vegas.
“We have colony forming unit or cfu that we routinely use in the probiotics industry provides meaningful information that indicates the amount of live organisms that would be in a dose. That would be the potency. But the milligram amount gives you the weight of the probiotic mixed with the excipients and it does not indicate viability at all. What we would like to see happen would be the cfu metric would be included for use in labeling for probiotics.
“FDA has made it clear that they, while they prefer to use the metric system it may not apply to probiotics, and they have encouraged us to submit a citizen’s petition.”
Analytic challenges and opportunities
In order to list the microorganisms as cfus, one needs to be able to count them, and this is an area of technical advances, said Smith. The current gold standard is to plate the organism in petri dishes and then count, which gives you the cfu’s. However, such counts are not consistent and one person will get a different result than another, with differences up to 30% observed.
“So, there has been a progression in methods and flow cytometry is one of them. This gives a total cfu and it’s a reliable method with low variability, but it does have some limitations. It provides a number for healthy cells, cells that are not mixed with excipients, and cells that are a single strain and not in a blend,” explained Smith.
DuPont has been looking at molecular methods to use the genetic tools that we have available. The company has come up with strain specific molecular methods that allow you to identify a number of strains within a blend or a mix of strains together in a product. For enumeration we’re using digital PCR, which enables a sample to be partitioned to where its one genetic code in each sample and there’s a fluorescent dye that would indicate that the sample is there and that this counts as one. And through the distribution and calculation it would give enumeration of only viable cells with low variability less than 5%. It’s a much more reliable method and it’s a faster test.
The company will be coming out with a publication of the method around November. “Then we’re hoping we can present this method to FDA and see if it would be acceptable for use in the industry.”
IPA’s DC Workshop
A workshop hosted by the International Probiotics Association will cover the NDI draft guidance and the GRAS final rule, analytical methods and potential new technology, probiotics labelling and best practices guideline, market sizing, claims substantiation, and discussing the role of the media.
For more information and to register, please click HERE.