While “Nanotechnology” may be defined in different ways, depending on the application, the term “Nanotechnology” is generally used to refer to the development of materials that have at least one measured dimension in the range of 1-100 nanometers (1 nanometer = 1 billionth of a meter). Practitioners in the fields of physics, engineering, chemistry, and materials sciences have been using Nanotechnology for more than twenty years to develop a variety of “nanomaterials” (e.g., nanoparticles, nanofibers, and nanotubes). The technology depends on novel techniques that have enabled the creation of these materials using either a “bottom-up” approach by building them up from the atomic scale; or a “top-down” approach in which larger-sized materials are made smaller (e.g., making smaller particles of titanium dioxide from larger particles). Nanomaterials may be sophisticated structures or devices that are created (“nanoengineered”) to perform specialized functions, or they may simply be smaller versions of larger materials (“nanoscale”).
Nanoscale materials are being developed because they exhibit different physicochemical properties than their chemically identical but larger-scale counterparts. Products containing nanoscale materials may thus offer advantages over similar products that contain the same materials on a larger scale. Some of the advantages that have been identified for nanoscale materials include increased strength and structural integrity, improved electrical conductivity, improved texture, enhanced stain resistance, longer shelf life, and improved UV protection. Examples of categories of consumer products that may incorporate nanoscale materials include drug delivery systems and medical devices, medical diagnostics, surgical instruments, clothing, wear-resistant coatings and paint, electronics; and personal care products.
The application of Nanotechnology to consumer products regulated by the FDA, including cosmetics and Over-the-Counter (OTC) drug products, has proven to be of great benefit to consumers. The use of nanoscale materials in consumer products is not new, as nanoscale particles of titanium dioxide and zinc oxide have been used in sunscreens for many years. The use of small particles of titanium dioxide and/or zinc oxide in sunscreens affords greater skin protection by increasing the ability of the product to block UV irradiation. Furthermore, the use of small particles in the formulation of sunscreens results in a clear protective barrier that is easier to apply and more aesthetically pleasing in texture to consumers than earlier opaque versions with larger particles, thus leading to greater consumer acceptance and use. Both of these factors ultimately contribute to a greater public health benefit by protecting individuals from the harmful effects of the sun, including skin aging and skin cancer.
Some personal care products may contain nanoscale particles of titanium dioxide and zinc oxide that are used as active ingredients in sunscreen products and have been approved for use by the Food and Drug Administration (FDA) since 1999. These nanoscale particles have been developed by breaking down larger particles during the manufacturing process. Titanium Dioxide and Zinc Oxide have been extensively evaluated and the scientific data shows that they do not penetrate the skin. The FDA has recognized that the science and applications of nanotechnology are developing at a very rapid pace, and that properties relevant to product safety and effectiveness may change as size varies with the nanoscale, adding additional complexity to the review of products containing nanotechnology materials. In August 2006, the FDA formed a Nanotechnology Task Force to determine regulatory approaches that encourage the continued development of innovative, safe and effective FDA-regulated products that use nanotechnology materials. In July 2007, the Task Force issued a report on the use of such materials. The report, which was endorsed by the FDA Commissioner, stated that "the current science does not support a finding that classes of products with nanoscale materials necessarily present greater safety concerns than classes of products without nanoscale materials," and concluded that there is no need for products containing nanoscale materials to be labeled as such. Link to FDA Nanotechnology Task Force's Report of July 2007: http://www.fda.gov/nanotechnology/nano_tf.html Comprehensive comments were submitted to FDA by the cosmetic industry that addressed the safety of nanoscale ingredients, such as titanium dioxide and zinc oxide as sunscreen active ingredients in personal care products. The comments provide a detailed summary of the data supporting the safety of these nanoscale ingredients in cosmetic and OTC drug products. Additionally, the remarks also provided a detailed analysis supporting the adequacy of FDA’s current regulatory scheme. Specifically, the Agency has ample authority to regulate personal care products, including those that contain nanoscale ingredients. Link to the industry comments filed with the FDA: http://www.fda.gov/ohrms/dockets/dockets/06n0107/06n-0107-c000014-01-vol... The use of micronized Titanium Dioxide and Zinc Oxide in sunscreen is common, and consumers have not reported toxicities or deleterious effects from these products. The addition of any nanoscale material to FDA-regulated products is subject to the applicable laws and regulations that have been developed to ensure safety. Further, the scientific methods currently used to test the safety of existing and new substances that may be used as ingredients of personal care products have been judged to be equally appropriate for evaluating the safety of ingredients developed in the nanoscale range. Finally, recent studies to evaluate the skin penetration of microfine titanium dioxide and zinc oxide demonstrate that these materials do not penetrate beyond the surface layers of the skin (i.e., the epidermis). For example, FDA is studying the ability of nano-sized materials to penetrate through the protective barrier of the skin. At the 2007 annual meeting of the Society of Toxicology, FDA scientists presented the results from their studies using Quantum Dots (Qdots) (reference 1). Qdots are a special form of nano-particle that, while not used in cosmetics, are a useful model for studying the behavior of these small particles. FDA concluded that it “appears that absorbed Qdots were found predominately in the stratum corneum and they did not penetrate through the skin”. These results are consistent with research that has been conducted using other nano-particles. Link to FDA public meeting on Nanotechnology held on October 10, 2006 http://www.fda.gov/Nanotechnology/meeting1010.html Presentation by Dr. Annette Santamaria at the FDA public meeting on Nanotechnology: http://www.fda.gov/ohrms/dockets/dockets/06n0107/06n-0107-ts00002-santam... According to a statement in 2006 by the National Toxicology Program (NTP), "[i]t is not known if these nanoscale particles (one dimension less than 100 nm) will penetrate the skin, and whether their photocatalytic properties will induce toxicity in the skin when irradiated." The NTP has separately noted that "there is very little research focused on the potential toxicity of manufactured nanoscale materials." As noted above, data developed since this statement have shown that nanoscale Titanium Dioxide and Zinc Oxide do not penetrate through the skin. NTP Center for Phototoxicology, FDA-NIEHS Phototoxicology Research and Testing Laboratory: http://ntp.niehs.nih.gov/files/NCPFacts061.pdf NTP, Nanotechnology Safety Initiative, Frequently Asked Questions (FAQ's): http://ntp.niehs.nih.gov/ntpweb/index.cfm?objectid=30302D16-F1F6-975E-7B...
Other Nanoscale materials, such as carbon fullerenes (also known as "buckeyballs"), have been reported to be used in some cosmetic products because of their antioxidative properties. However, their use in personal care products is very limited. While there have been some reports that certain chemical forms of fullerenes may produce toxic effects, these effects were observed in studies under exaggerated conditions irrelevant to the human exposure situation. Adverse effects have not been reported following the application of fullerenes in lower concentrations in formulations such as a topically applied lotion or cream. Further, the toxicological potential of nanoscale materials such as fullerenes can be evaluated through current safety evaluation processes, and these materials would only be used in products once their safety was confirmed. Some products report the use of “Nanosomes”. Nanosomes are really small droplets of ingredients that are produced through careful mixing. They have been around for several decades and are also known as “Liposomes”. These small droplets, which are capsules containing an outer cover that can be used as a container for other ingredients, are different from nanotechnology as generally understood. When applied to the skin, Nanosomes (or liposomes) dissolve and release their contents onto the surface of the skin, just as the ingredients in ordinary creams and lotions do. The benefit of nanosome/liposome is that they can more effectively deliver moisturizing ingredients to the surface of the skin. Liposomes have also found application in the formulation of drug products where ingredients that are very sensitive or unstable can be “packaged” into capsules so that they can provide the intended therapeutic benefits.
There is an enormous amount of information available about Nanotechnology. The following provided to highlight some of these sources: FDA Nanotechnology Activities: http://www.fda.gov/Nanotechnology/ FDA Docket for Nanotechnology: http://www.fda.gov/ohrms/dockets/dockets/06n0107/06n0107.htm The US National Nanotechnology Initiative: http://www.nano.gov/ The International Small Technology Network: http://www.Nanotechnology.com/ The Woodrow Wilson Center Project on Emerging Nanotechnologies: http://www.nanotechproject.org/ Nanotechnology Homepage of the European Commission: http://cordis.europa.eu/nanotechnology/ References: (1) Kraeling, ME, Gopee, NV, Roberts, DW, Ogunsola, OA, Walker, NJ, Yu, WW, Colvin, VL, Howard, PC and Bronaugh, RL. (2007) Evaluation of in vitro penetration of quantum dot nanoparticles into human skin. The Toxicologist 96: 289