While nanotechnology use in cosmeceuticals is promising, safety concerns remain about widespread use of “nanocosmeceuticals” for skin, hair, nail and lip care, researchers from India report in a review published earlier this year.
That thinking is reflected in the U.S. where large companies in the cosmetics industry have voluntarily agreed not to use nanoparticles in currently marketed products because of those safety concerns, according to dermatologist Zoe Diana Draelos, M.D., who practices in High Point, N.C., and founded Dermatology Consulting Services, a company that works with cosmeceutical firms to develop formulations and conduct product testing.
Nanoparticle Safety Concerns
In essence, nanotechnology involves putting particles that are less than 100 nanometers (nm) into a formulation.
“These are particles of any material,” Dr. Draelos says. “In the cosmeceutical world, typically the nanoparticles would be part of the active agents or the hero ingredient that’s designed to deliver on some cosmetic claim.”
The concern is that nanoparticles are so small that they can penetrate into appendageal structures, like hair follicles. They can the penetrate stratum corneum, theoretically entering the body.
While safety concerns have kept many cosmetic and cosmeceutical companies from promoting nanotechnology as a benefit, nanoparticles are, in fact, in many of today’s products. Nanoparticles might be an unintentional consequence due to the manufacturing process for raw materials. Dr. Draelos cites the example of titanium dioxide and zinc oxide, which are minerals from rocks ground to a small particle size for topical sunscreens. Grinding zinc oxide and titanium oxide small enough so applying sunscreen doesn’t make the skin so white might result in creating nanoparticles.
Another example is in the manufacturing process for cosmetics with pigment, such as eyeshadow, or to make the reflective, frosted, glittery effects of other makeup types. Companies might end up using nanoparticle sized mica or fish scales to create the glittery look, according to Dr. Draelos.
“Back to the example of zinc oxide and titanium oxide: Imagine if you had nano-sized zinc oxide and titanium dioxide, you could actually get those particles in your skin and they would be there for the rest of your life, unless your immune system phagocytized the material and initiated removal,” she says.