Napp Pharmaceutical Holdings Ltd v Ratiopharm GmbH

A pharmaceutical patent claim expressed as “comprising” specified elements may cover a product containing an additional feature, provided every claimed element is present. Functional claim language is construed purposively in the context of the specification and the skilled person’s understanding.

An amendment adds matter only if the skilled person would learn something about the invention which was not clearly and unambiguously disclosed, expressly or implicitly, in the application as filed. An undisclosed disclaimer is governed by that same test. It is permissible where it merely removes protection and makes no technical contribution.

For obviousness, the skilled person’s motivation remains relevant. A predictable development is not necessarily obvious where there was no apparent reason to undertake it. An unexpected advantage fails to support inventiveness only where another real motive would have led the skilled person to use the idea.

Napp owned two divisional patents concerning 12-hour controlled-release formulations of oxycodone. Ratiopharm GmbH and Sandoz Ltd intended to market tablets in which 80% of the oxycodone was released through a polymer coating and approximately 20% was applied outside that coating for immediate release.

Floyd J held that both patents were valid but that the proposed tablets did not infringe. Napp appealed on infringement. The generic manufacturers challenged validity by cross-appeal, alleging added matter and obviousness over an earlier patent known as Oshlack.

The central questions were how the claims should be construed, whether the divisional patents disclosed impermissible added matter, and whether a 12-hour controlled-release oxycodone formulation was obvious in light of Oshlack.

1. Napp’s appeal was allowed and the generic manufacturers’ validity appeal was dismissed. The patents were valid and infringed. The judgment was the judgment of the court, to which all three members contributed.

2. The term “spheroid” was not confined to particles produced by extrusion and spheronisation. It covered spheroidal particles made up of smaller particles by any suitable process. “Spheronising agent” was likewise not confined to non-water-soluble materials used in extrusion. HPMC fell within the patent’s functional definition because it assisted in forming the relevant oxycodone-containing spheroids. Its additional function as a binder or matrix did not prevent it from being a spheronising agent.

3. A product satisfying the elements of a claim was not removed from the claim merely because some oxycodone was applied outside the controlled-release coating. The word “comprising” did not mean “consisting only of”. Claim 1 of the second patent was infringed where the coated portion satisfied the specified structural elements and the dosage form as a whole satisfied the dissolution requirements. Claim 6 of the first patent was construed similarly.

4. “Measured by the USP Paddle Method” required use of the specified apparatus and experimental method. It did not incorporate the USP batch-acceptance criteria. The claim was directed to an individual dosage form, and infringement was established where an individual tablet fell within the claimed dissolution parameters.

5. Under article 123(2) of the European Patent Convention, the comparison is between the application as filed and the patent under challenge. Added matter exists where the skilled addressee learns subject matter relevant to the invention which was not clearly and unambiguously disclosed, expressly or implicitly, in the application. Claim breadth must not be equated with disclosure.

6. There was no separate rule invalidating disclaimers used when dividing an application. The controlling question remained whether the amendment added subject matter. A disclaimer which merely removed protection, conferred no unwarranted advantage and made no technical contribution did not contravene article 123(2). Neither the acrylic-resin disclaimer nor the claims concerning spheronising agents added matter.

7. The obviousness challenge failed. Oshlack concerned a controlled-release matrix and supplied no reason to develop oxycodone as a 12-hour alternative to morphine. A formulator would not embark on a development programme merely because the necessary formulation work might be predictable. Motivation remained relevant. The case was unlike an unexpected-advantage case in which the skilled person already had a real reason to use the proposed idea.

1. Court of Appeal (Civil Division): By [2009] EWCA Civ 252, allowed Napp’s appeal on infringement and dismissed the generic manufacturers’ appeal on validity. The patents were held valid and infringed.

2. High Court, Patents Court: Floyd J held both patents valid but found that the proposed tablets did not infringe. The judgment was delivered on 16 December 2008; no neutral citation is stated in this judgment.