TGA rising to the challenge of nanomaterials in medicines

From the increasing level of media interest and international government activity in the area, one could be forgiven for believing that nanotechnology is a very recent phenomenon arising only in the last five years or so. In actual fact, the TGA has been assessing and regulating nanomaterials for some decades, although not always under that description. This is not to say that the technology does not present significant scientific and policy challenges, as indeed it does. The TGA is responding to these challenges by contributing its considerable experience and expertise in national forums addressing the policy and regulatory response to the increasing sophistication and broad application of nanotechnology.

There is a considerable blur between materials that might legitimately be described as macromolecules and those that in more recent times would be described as nanomaterials or the product of nanotechnology. Drug carrying liposomes with nanometre diameters, pegylated proteins with molecular diameters in that range and nanoparticle suspensions to improve bioavailability are some of the more common nanomaterials encountered over the past decade. One of the first nanomaterials encountered by the TGA was Technegas™, a lung contrast imaging agent consisting of hexagonal flat crystals of technetium metal cocooned in multiple layers of graphite sheets. A technology developed right here in Canberra in the mid-1980s, as it happens.

One of the key concerns raised by many commentators in the public arena is that of the potentially unique hazards associated with nanomaterials and the capacity of existing regulatory paradigms to adequately identify and manage such risks. While it is true that nanomaterials may, and often do, have different physical and chemical characteristics compared to the same material at larger particle sizes, these differences may either increase or decrease the toxicity of that material. Equally there is currently no evidence for any unique toxicological hazards associated with nanomaterials. Certainly, some nanomaterials potentially present significant hazards which will need to be carefully managed, but the specific toxicological endpoints involved have previously been observed with other, soluble or larger particle size, materials.

The TGA has a significant advantage in the regulation of products incorporating nanomaterials in that it

• generally operates in a data rich environment
• has a high level of expertise to bring to bear on the assessment of new technologies
• has the legislated authority to require additional data in support of the safety assessment of new materials where this is warranted
• and, in the most part, deals with sponsors who have the technical expertise to adequately address key safety issues.

In the medicines area in particular, the level of data provided in support of the registration of new products is very extensive and covers the full range of endpoints relevant to the risk assessment of such materials.

Nanotechnology and other emergent new technologies will continue to present substantial policy and scientific challenges to the TGA into the future. The best response to such challenges is the maintenance and continued development of high quality scientific expertise within the agency together with ongoing interaction with sponsors, researchers, regulators and policy makers throughout Australia and internationally, to which the TGA is committed. The TGA will continue to closely monitor developments around nanotechnology internationally to ensure a rapid response to any new issues identified.

Pharmacovigilance visitor

Ms Lise Aagaard from the Danish Medicines Agency attended the TGA's Adverse Drug Reactions Unit from 5 February to 2 March 2007. Lise is researching comparative pharmacovigilance systems in Denmark and Australia for her PhD. While with the Adverse Drug Reactions Unit, Lise attended a meeting of the Adverse Drug Reactions Advisory Committee and had full access to the TGA's pharmacovigilance systems. Lise also gave a presentation on Pharmacovigilance in the Danish Medicines Agency and Medicines Regulation in Europe that was attended by staff from throughout the TGA.