Narrow Claim Construction Avoids Invalidity Based on Prior Art

Based on narrow claim construction, the U.S. Court of Appeals for the Federal Circuit affirmed a lower court’s holding that ALZA Corporation’s (ALZA) patent is not anticipated or obvious in view of the prior art and that the patent is not unenforceable as having been procured by inequitable conduct. ALZA Corp. v. Mylan Laboratories Inc., Case No. 04-1344 (Fed. Cir., Dec. 10, 2004) (Archer J.; Dyk, J. concurring-in-part and dissenting-in-part).

ALZA’s `580 patent is directed to a system for the transdermal administration of the narcotic fentanyl, marketed as the Duragesic patch. Prior to the invention disclosed in the `580 patent, attempts at transdermal patches for fentanyl delivery had been unsuccessful due to low skin permability of fentanyl citrate, the traditionally administered form of the drug. The inventors of the `580 patent discovered that the skin permeability of fentanyl was highly dependent on the chemical form of the drug and that the base form of fentanyl should be