Cadence Pharmaceuticals, Inc. v. Paddock Laboratories Inc.
886 F. Supp. 2d 445
D. Del.2012Background
- This is a claim construction (Markman) dispute over U.S. Patent Nos. 6,028,222 and 6,992,218 related to liquid acetaminophen formulations and deoxygenation methods.
- Plaintiffs Cadence Pharmaceuticals, Inc. and SCR Pharmatop sue multiple defendants for infringement and seek construction of disputed terms.
- The '222 patent addresses stability by including a buffering agent and a free radical scavenger/antagonist in the acetaminophen formulation.
- The '218 patent describes an extreme deoxygenation process to reduce or remove oxygen from the formulation during manufacturing.
- The court held a Markman hearing and issued constructions guiding interpretation of the disputed terms.
- The constructions focus on stability, aqueous medium, buffers, antioxidants, osmotic/ion-related terms, dilution limits, and deoxygenation steps.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Is 'stable' indefinite or definite? | Cadence argues stable is definite with a meaningful meaning in the art. | Perrigo/Paddock argue indefiniteness under 35 U.S.C. § 112, ¶ 2. | Stable is definite and construed as non-decomposition with pharmaceutically acceptable shelf life. |
| What does 'liquid formulation consisting essentially of acetaminophen dispersed in an aqueous medium' mean? | Cadence argues broad but accurate scope including water-rich and mixed aqueous media. | Defendants argue narrowing to stability-focused constituents; water/polyhydric compounds and alcohols included. | Means a solution of acetaminophen dissolved in a medium containing water or water-containing mixtures with polyhydric compounds and/or water-soluble alcohol. |
| What is the proper meaning of 'a buffering agent'? | Cadence seeks a broad buffering role in maintaining pH. | Defendants propose an acid/base constrained system. | An agent that helps the formulation resist change in pH. |
| How should 'free radical scavenger' and 'free radical antagonist' be construed? | Cadence requires scavenging of free radicals. | Antioxidant function suffices without explicit scavenging language. | Substance that functions in the formulation as an antioxidant. |
| What is the meaning of 'an isotonizing agent'? | Cadence seeks osmotic pressure adjustment for infusion. | Defined by osmotic similarity to physiological fluids. | A substance used to make the osmotic pressure of the formulation more similar to physiological fluids. |
Key Cases Cited
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (claims define the invention; consider intrinsic/extrinsic evidence)
- Markman v. Westview Instruments, Inc., 52 F.3d 967 (Fed. Cir. 1995) (claim construction is a question of law)
- Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir. 1996) (specification is highly relevant to claim construction)
- Sun-Rice Roots Enter. Co., Ltd. v. SRAM Corp., 336 F.3d 1298 (Fed. Cir. 2003) (use of dependent claims as guide to claim scope)
- Renishaw PLC v. Marposs Societa’ per Azioni, 158 F.3d 1243 (Fed. Cir. 1998) (claim construction should stay true to claim language)
- Osram GmbH v. Int'l Trade Comm’n, 505 F.3d 1351 (Fed. Cir. 2007) (avoid reading limitations from spec as claim limitations)
- Cohesive Techs. Inc. v. Waters Corp., 543 F.3d 1351 (Fed. Cir. 2008) (extrinsic evidence supports intrinsic, but not override)
- Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314 (Fed. Cir. 2003) (disclaimer and prosecution history limitations require clear disavowal)
- Power-One, Inc. v. Artesyn Techs., Inc., 599 F.3d 1343 (Fed. Cir. 2010) (indefiniteness requires insoluble ambiguity; not merely difficult)
- Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244 (Fed. Cir. 2008) (indefiniteness and claim construction considerations)
- Wellman, Inc. v. Eastman Chem. Co., 642 F.3d 1355 (Fed. Cir. 2011) (patent disclosure need not repeat well-known industry standards)