Santarus, Inc. v. Par Pharmaceutical, Inc.: Is there a new written description requirement for negative limitations?

Abstract

In Santarus, Inc. et al. v. Par Pharmaceutical, Inc., 694 F.3d 1344 (Fed. Cir. 2012), the Federal Circuit addressed the written description requirement for patent claims containing a negative limitation (i.e., “wherein the composition contains no sucralfate”). This case report presents the context surrounding that issue including the concern by one Federal Circuit judge that a new written description requirement was created for negative claim limitations that would “taint large numbers of issued patents.”