Ratiopharm GMBH v NAPP Pharmaceutical Holdings Ltd

In construing a patent claim, the court asks what the skilled person would understand the patentee to mean from the claim language read in context. A claim to a dosage form may be limited to the total quantity of active ingredient, while a differently drafted independent claim may not carry the same limitation.

For added matter, the question is whether the amended patent discloses subject matter relevant to the invention which was not clearly and unambiguously disclosed in the application as filed. A divisional application does not create a general exception for otherwise undisclosed disclaimers.

Obviousness must be assessed using the structured approach in Pozzoli v BDMO SA. Common general knowledge must be precisely identified and established. A development programme which could be undertaken with sufficient motivation is not necessarily obvious without a proper rationale.

These conjoined patent actions concerned European Patent (UK) Nos 722730 and 1258246, owned by Napp Pharmaceutical Holdings Ltd. Ratiopharm GmbH and Sandoz Ltd originally sought revocation and declarations of non-infringement. The proceedings became infringement actions when Napp counterclaimed against their proposed oxycodone products.

The issues included construction of claims concerning controlled-release oxycodone formulations, infringement by the Cimex product, added matter, and obviousness over common general knowledge, Oshlack and Goldie. Napp also sought amendments to one patent and made an unopposed application to amend the other.

1. Construction and infringement. Claim 1 of patent 246 required all the oxycodone in the dosage form to be within the film coating. Claim 4, being dependent on claim 1, was no wider in that respect. Claim 6 of patent 730 was differently worded and did not require all the oxycodone to be within the spheroids. The term “matrix” required a structure which held the oxycodone and allowed release to be controlled by the coating. “Spheroid” meant a generally spherical granule, without limiting the manufacturing process. A “spheronising agent” meant an agent which enabled the excipients to form into a sphere; it did not include material added after the sphere had been formed.
2. The Cimex particles were granules and contained a matrix, but the HPMC was a binder or matrix and not a spheronising agent. Claim 6 of patent 730 was therefore not infringed. The significant quantity of oxycodone outside the release coating also prevented infringement of claims 1 and 4 of patent 246. Neither patent was infringed.
3. Added matter. The test was whether the disclosure of the application and patent, construed through the eyes of the skilled addressee, differed by the addition of subject matter relevant to the invention. There was no general exception for an undisclosed disclaimer inserted in a divisional application. The disclaimer excluding pH-independent acrylic resin matrices did not add relevant technical subject matter or confer an unwarranted advantage. The acrylic resin, intermediate generalisation and spheroids objections therefore failed.
4. Obviousness. The court applied the four-stage approach in Pozzoli v BDMO SA. The skilled team included access to formulation, clinical and pharmacological expertise. In 1991, oxycodone was generally known as a co-drug for mild to moderate pain, but was not common general knowledge as an oral alternative to morphine for moderate to severe pain. The claimed controlled-release oxycodone formulations were consequently not obvious over common general knowledge.
5. Oshlack disclosed controlled-release oxycodone but did not present oxycodone as an alternative to morphine. It would prompt investigation of its formulation example, not the wider development programme needed to reach the claims. Goldie concerned hydromorphone and gave no sufficient rationale for undertaking equivalent development with oxycodone. The claims were not obvious over either document.
6. The application to amend patent 246 was allowed. The conditional application concerning patent 730 did not arise because invalidity had not been established.

First-instance decision. The judgment itself records no prior appellate decision in the same litigation.