Extension of term of drug delivery system patents in Australia

Extension of term of drug delivery system patents in Australia

Extension of term of drug delivery system patents in Australia

This article was first published in the Royal Society of Chemistry Law Group Newsletter, February 2010. Reproduced by permission of The Royal Society of Chemistry (RSC).

Under Australian patent law it is possible to extend the term of pharmaceutical patents. The provisions are similar to those provided by the European Union supplementary protection certificate (SPC).

To be eligible for an extension of term in Australia: a patent must claim and in substance disclose one or more pharmaceutical substances per se; a product which contains the pharmaceutical substance must be included in the Australian Register of Therapeutic Goods (ARTG)1; and the first regulatory approval date for the pharmaceutical substance must have occurred more than five years after the date of filing the patent.

The term “pharmaceutical substance” is legislatively defined as a substance (including a mixture or compound of substances) for therapeutic use.2 Further, the meaning of “pharmaceutical substance per se” has been judicially considered and held to mean that an extension of term is limited to those patents in which a pharmaceutical substance is claimed “by or in itself”.3 In other words, claims to a pharmaceutical substance in a drug delivery system are not considered to be directed to “a pharmaceutical substance per se” unless the pharmaceutical substance itself (or combination of substances) is new and inventive.

However, following a decision in 20074 the Australian Patent Office (APO) appeared to accept a broader definition for the term by allowing a request to extend the term of a patent relating to a controlled-release formulation of zolpidem tartrate with a bi-phasic dissolution bilayered tablet containing an immediate release layer and a prolonged release layer. In this case the term “compound” in the definition of a “pharmaceutical substance” was interpreted to include a compound formed by “combining elements or parts, or creating a union of parts” such as the biphasic tablet.

The situation has been further clarified by a recent decision in which the APO allowed an application to extend the term of a patent directed to a delivery system adapted to the slow release of steroidal mixtures contained in a thermoplastic polymer core overlaid with permeable thermoplastic skin. In this case it was held that the thermoplastic materials “have a physical purpose to position, contain and provide for the controlled release of the steroidal components”, and as such, the product as a whole was considered to exhibit a level of integration or interaction between the component parts more characteristic of a pharmaceutical substance in itself than a substance combined with another element or thing.

In light of these recent decisions it would seem that patents claiming drug delivery systems, which were previously denied an extension in Australia, may now be eligible.

Endnotes

  1. In other words be registered with the Australian regulatory authority the Therapeutic Goods Administration (TGA).
  2. The therapeutic use must involve: (a) a chemical interaction, or physicochemical interaction, with a human physiological system; or (b) action on an infectious agent, or on a toxin or other poison, in a human body; but does not include a substance that is solely for use in in vitro diagnosis or in vitro testing.
  3. Boehringer Ingelheim International GmbH v Commissioner of Patents [2001] FCA 647.
  4. Sanofi-Aventis [2007] APO 35.