3.12.1.4 Meaning of "mixture or compound of substances"

The definition of a “pharmaceutical substance” provided in schedule 1 refers to:

"a substance (including a mixture or compound of substances) for therapeutic use …”.

Other than the passing remarks made by Burchett J that the expression “a mixture or compound of substances” was unusual in a scientific context (Virbac (Australia) Pty Limited and Ancare Distributors Limited v Merck Patent GmbH [1994] FCA 1255), this phrase has not been the subject of judicial consideration. However, it has been the subject of Office decisions including Sanofi-Aventis [2007] APO 35 and N. V. Organon [2009] APO 8.

In Sanofi (supra), the claims were to a biphasic composition presented in the product as a bi-layered tablet.  In N. V. Organon (supra), the invention involved a steroidal mixture contained in a thermoplastic polymer core, over which was laid a permeable thermoplastic skin through which the steroidal mixture diffused and was delivered in use.

More specifically, in N. V. Organon (supra) it was stated:

“In this light it appears to me that a pharmaceutical substance (including a mixture or compound of substances) can include a compound with a controlled spatial configuration if, as a whole, it can still be considered a pharmaceutical “substance” but the combination of such a substance with what would reasonably be considered a separate physical device, layer or structure or, from Sanofi, “any purely physical integers” is excluded and indeed would not be a “pharmaceutical substance per se”.”

It was recognised that it may be difficult to determine whether a particular feature of a product is correctly considered part of a “substance” rather than a separate physical integer.  However, in the circumstances of that case, it was found that the product as a whole exhibited a level of integration or interaction between the component parts that was considered more characteristic of a pharmaceutical substance itself, rather than a substance combined with another element or integer.

It therefore follows that other inventions which potentially involve a spatial configuration need to be considered on their merits.

There is also a need to consider whether a composition claim encompasses a single pharmaceutical substance or a mixture or compound of substances. Where the claim is directed to a mixture or compound of substances, the same must also be found in the goods.