Warner Chilcott Laboratories Ir., Ltd. v. Impax Laboratories, Inc.

Patent infringement cannot be shown where the alleged infringers do not directly apply, and accepted testing method do not show the presence of, the patented substance.

Opinion (Martini): Mayne Pharmaceuticals International Pty. Ltd. (Mayne) owned patent number 6,958,161 (’161), which described a modified release coating that controls the rate at which active pharmaceutical ingredients are released after ingestion. Warner Chilcott Laboratories Ireland Ltd. held the exclusive right to market and sell drugs using the ’161 patent, which it marketed under the name Dorxy Delayed Release Tablets. Mayne and Warner filed suit against Mylan Pharmaceuticals, Inc. (Mylan) and Impex Laboratories, Inc. (Impax), claiming their filing of Abbreviated New Drug Applications with the FDA, seeking approval to sell generic versions of Dorxy Tablets, infringed the ’161 patent. Mylan and Impex denied infringement, and asserted that the patent was invalid on grounds of anticipation and obviousness. Following a consolidated bench trial, the District Court held that neither generic formulation infringed the ’161 patent, because neither manufacturer applied the stabilizing coat required to infringe the patent in their manufacturing processes, and because Mayne and Chilcott could not establish the presence of the coating in either formulation by any of the five scientifically accepted tests. The District Court rejected Mylan and Impex’s allegations that the ’161 patent were invalid, finding that its stability, coating, and active ingredient limitations were not anticipated or obvious in light of prior art. The District Court REJECTED Mylan and Impex’s infringement claim.