How nanomaterials are defined profoundly affect how they are regulated, she pointed out. For an example, Dr. Kulinowski showed how the EPA evolved in its regulation of nanomaterials. Initially the agency claimed that nanomaterials were not considered new chemicals, with more of an emphasis on the molecular identity of the material and not its size, shape, or surface. The agency regulated nanomaterials as falling under the domain of the Toxic Substances Control Act, and engaged in a voluntary data gathering approach initially. But now the EPA is starting to define nanoscale materials as new uses of existing chemicals, she said, which allows the agency to impose some additional reporting requirements, toxicology testing, and specific mandates for worker protection, as well as mandatory data collection.
“The EPA is shifting their emphasis from a very specific chemical definition of how the atoms are connected, to how does it act, what does it do, is it biologically or environmentally different, and does it have different physical and chemical properties that could matter in an environmental or biological system,” Dr. Kulinowski said.
Several speakers called for more standards in terminology and metrics. Dr. Desai noted the importance of having an appropriate descriptive term in the label or package insert of a nanomedicine so that the clinician and patients fully understand what they are using and can make an informed decision. But Abraxane’s particle size is 130 nanometers (nm) so the FDA did not allow his company to call Abraxane a nanoparticle because it was bigger than their 100 nm cutoff for nanoproducts. He added that other regulatory agencies internationally accepted Abraxane being labeled as a nanoparticle.
Dr. Sackner-Bernstein implied there might be flexibility in the FDA definition of nanotechnology. “It’s about size and properties, but basically if you think it’s going to behave differently, come talk to us. The last thing anybody wants is for a product to get far along and then to discover a problem. Discussing this up front, even if you’re not sure, is a way to address this issue,” he said. Quoting from an FDA document (FDA, 2009). Dr. Duncan added “It is quite likely that new therapeutic benefits are being derived from products that are smaller than their traditional form, but fall above the 100 nm size-range limit of nanotechnology…. Particle size is not the issue. As new toxicological risks that derive from the new materials and/or new conformations of existing materials are identified, new tests will be required.”
Dr. Duncan stressed the importance of accurate categorization of materials and products. “What if we suddenly decided today that every transport system is called a plane. If we try and control a boat or a bicycle or a train using the same regulation we use for a plane it is not helpful.” Dr. Gaspar agreed, “This is not irrelevant, because the problem is that