FDA Issues Nanotech Draft Guidances

WASHINGTONFDA issued two draft guidance documents focusing on nanotechnology, one for use in foods and one for use in cosmetics. While neither of the draft guidance documents mentions supplements specifically, they have implication to this industry because they offer safety standards that can apply to dietary supplements.

Duffy MacKay, N.D., vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN) said he doesn't expect FDA to issue a nanotechnology draft guidance for use in dietary supplements. "This food one is what we're going to be left with," he said.

"Neither guidance is specifically directed to the dietary supplement industry; but as a category of food, dietary supplements can be affected specifically by the Guidance for Industry: Assessing the Effects of Significant Manufacturing Process Changes, Including Emerging Technologies, on the Safety and Regulatory Status of Food Ingredients and Food Contact Substances, Including Food Ingredients that are Color Additives," said Cara Welch, vice president of scientific and regulatory, the Natural Products Association (NPA). "The cosmetic guidance document might affect some dietary supplement companies that also have cosmetic product lines."

It is likely that FDA believes the food document applies to dietary supplements because in the new dietary ingredient (NDI) draft guidance, FDA listed nanotechnology that results in new or altered chemical properties of the ingredient as an example of a processes that creates a new dietary ingredient.

In the nanotechnology draft guidance for food, FDA said alterations in the physical and chemical properties of a food substance can affect its bioavailability through altered absorption, distribution, metabolism and excretion. "Such changes in the substances biological interactions can affect the level at which toxic effects may occur," the agency wrote.

Because nano-engineered food substances can significantly alter bioavailability, they raise new safety issues, according to the agency. "When a food substance is manufactured to include a particle size distribution shifted more fully into the nanometer range, safety assessments should be based on data relevant to the nanometer version of the food substance.  Where nano-engineered food substances have new properties, additional or different testing methods may be necessary to determine the safety of the food substance." 

Safety assessments should be as rigorous as possible and should be based on data relevant to the version of the food substance intended for use, according to FDA .

"If we know that substance X is safe because of safety studies, but you change the properties dramatically, for example increase the bioavailability by 10 times by turning it into a nanoparticle, they are saying is it is new, and you should redo the safety studies," MacKay said. "It's not enough to rely on the previous safety data. Now, you must reassess because you have an ingredient that behaves differently."

FDA said  the GRAS (general recognition of safety) criteria cannot be used for food with nanotechnology because food ingredients engineered on the nanometer scale do not have the generally available safety data that is the foundation of a GRAS determination.

"My initial read is that the dietary supplement industry needs to be aware of the status of each ingredient in their products," Welch said. "If the ingredients have food additives or GRAS status, does a change in their manufacturing process require additional safety assessments? "

In the cosmetics document, FDA also noted some nanomaterials have unique physicochemical properties that may alter the potential toxicity of a compound (e.g., reduction in particle size could increase the ability for the compound or its constituents to be absorbed).  The agency said the safety assessment of these products should address whether there will be an increase in uptake, absorption, transport into cells and transport across barriers (e.g. blood-brain barrier) or altered bioavailability or biological half-life. 

For products that could be absorption through the skin, FDA said studies should be conducted for intact skin and impaired skin (e.g., sunburned, atopic, eczematous, psotiatic skin) to address the possibility of an increased rate of penetration. 

For aerosolized cosmetic products, which can result in exposure to nanomaterials via the respiratory tract, extra care should be taken because FDA said studies have indicated that decreasing the size of particles increases the surface area, resulting in potential adverse effects not only in the respiratory system, but also in the heart and blood vessels, the central nervous system and the immune system.

For cosmetics that use nanotechnology, FDA recommended, at a minimum, testing for acute toxicity, skin irritation, dermal photoirritation, phototoxicity, skin sensitization, mutagenicity/genotoxicity, repeated dose (21 to 28 days) toxicity and subchronic (90 days) toxicity. "Results obtained from this basic test battery may indicate a need for additional testing," the agency wrote. Further, FDA said manufacturers should consider modifying traditional toxicity testing  as appropriate to account for nanotechnology and added new methods may also need to be developed. 

"The big deal may be in cosmetics," MacKay  said. "How far and easily something is absorbed into the skin is changed dramatically when you change how big the particles are. This might be a significant issue for them because cosmetics is a big area where this is technology is applied."

In the NDI Draft Guidance, FDA said it had not adopted a formal definition of "nanotechnology," "nanomaterial," "nanoscale," or related terms. In the absence of a formal definition, FDA said it considers the following points when determining a nanotechnology ingredient: 1."Whether an engineered material or end product has at least one dimension in the nanoscale range (approximately 1 nm to 100 nm); or 2. Whether an engineered material or end product exhibits properties or phenomena, including physical or chemical properties or biological effects, that are attributable to its dimension(s), even if these dimensions fall outside the nanoscale range, up to one micrometer."

MacKay  said CRN will look through the food draft guidance closely, share it with its members and get feedback. "We'll discuss it with our regulatory affairs committee and determine if there is anything in here that warrants us to respond specifically."

However, he added, "This isn't smack in the center of dietary supplements like something like the NDI draft guidance, but this may affect people working in technology. There are ingredients such as turmeric that have great properties, but aren't really that absorbable. Since this technology is out there to increase bioavailability, people may start to apply it more often. We have to determine how this affects our industry."

For more information:

Draft Guidance for Industry: Assessing the Effects of Significant Manufacturing Process Changes, including Emerging Technologies, on the Safety and Regulatory Status of Food Ingredients and Food Contact Substances, Including Food Ingredients that are Color Additives

Draft Guidance for Industry: Safety of Nanomaterials in Cosmetic Products

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