Omnicef isn't what it used to be. The widely used antibiotic had been a huge money-maker for Illinois-based Abbott Laboratories, bringing in billions of dollars in revenue. But in May 2007, the patent on the drug's composition expired. Competitors began making and selling generic versions of it. Abbott's revenue from U.S. sales of Omnicef plunged--going from $637 million in 2006, to $235 million in 2007, to just $25 million in 2008.
Abbott, however, still has one U.S. patent on the drug, known generically as cefdinir. The patent covers a crystalline form of cefdinir as well as a series of steps by which this chemical is "obtainable." And Abbott didn't let this patent--No. 4,935,507 ('507 patent)--sit idle.
Abbott does not offer guidelines for determining when something is a product-by-process claim. And unfortunately, the boundaries can be blurry. "For instance, there are product claims with process implied, and product claims with some kind of process limitation," Gollin says. He adds that even in Abbott, the eight members of the majority disagreed with the three dissenters over whether Abbott's '507 patent was a product-by-process patent.