Double Patenting is Alive and Well in the Federal Circuit

In re Metoprolol Succinate Patent Litigation, [2006-1254] (July 23, 2007) The Federal Circuit affirmed the district court's holding of invalidity for double patenting, but vacated the district court's inequitable conduct holding and remanded the case.
BRIEF: In March 1991 U.S. Patent No, 5,001,161 issued on metoprolol succinate with a sustained release pharmaceutically acceptable carrier. In January 1992 U.S. Patent No. 5,081,154 issued on metoprolol succinate. In October 1988 U.S. Patent No. 4,890,318 issued on an improved oral release composition comprising metoprolol succinate. The defendants moved for summary judgment of invalidity of the '161 and '154 patents for invalidity for double patenting and unenforceability. Astra appealed the grant of summary judgement of invalidity of the '154 patent, and of unenforceability of both patents. Non-statutory or obviousness type double patenting is a judicially created doctrine adopted to prevent claims in separate applications or patents that do not recite the same invention, but nonetheless claim inventions so alike that granting both exclusive rights would effectively extend the life of patent protection.
The Federal Circuit agreed that a patent on Metoprolol was a double patent of an earlier patent on Metoprolol and pharmaceutically acceptable carriers. The Federal Circuit reversed the finding of unenforceability because the court erred in equating the presence of an incentive to device with intent to deceive.