The evidence around nanotechnology

Nanotechnology has been used by the largest cosmetic companies for decades, according to Adam Friedman, M.D., assistant professor of medicine (dermatology), physiology and biophysics at Montefiore - Albert Einstein College of Medicine, Bronx, New York.

Nano, itself, refers to the size range (1 to 100 billionth of a meter). But, equally important, is the unique phenomena that emerge at this size, as the physical, optical and chemical properties can be altered and manipulated, Dr. Friedman says.

“The FDA (Food and Drug Administration) just came out with its final guidance - a guidebook to how companies should evaluate nanomaterials in cosmetics. It’s a recommendation for how companies can work with the FDA to make sure that what they’re using is safe, and there’s full transparency with respect to the properties of the nanomaterials utilizes,” Dr. Friedman says.

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The benefits of nanotechnology are especially clear in the sunscreen space, Dr. Friedmansays. Using nanotechnology can help change the texture of otherwise goopy ingredients, such as titanium dioxide and zinc oxide, as well as their bright chalky white appearance on the skin.

“You’re changing these established and effective UV filters’ ability to scatter visible light, so they are less apparent when applied but still scatter UV” he says. “(The smaller particles possible with nanotechnology) sit within natural imperfections of the skin more evenly. It’s retained on the skin and, at the end of the day, it’s a more effective sunscreen than your traditional formulation.”

The concern, according to the dermatologist, is that these filters are photocatalysts, which means they generate free radicals when exposed to ultraviolet radiation. Despite this, traditional mineral sun blocking agents have a well-established safety record, according to Dr. Friedman.

“The concern on a nano scale is: Are they actually penetrating the skin? Are they getting into cells? If yes, are they causing damage to the DNA, to lipids, proteins through this production of free radicals?” Dr. Friedman says. “All evidence to date suggests they do not get into the skin. They do not get into the cells. They do not cause damage. There have been numerous ex vivo pig and clinical studies, some using remarkable noninvasive real-time imaging to show lack of penetration. Obviously, though, more data is always a good thing.”

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