Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC, No. 04 C 346, 2007 WL 1468630 (N.D. Ill. May 18, 2007) (Zagel, J.).

Judge Zagel construed the claims of the parties’ patents, each to chewing gum containing physiological cooling agents.  The Court first construed "menthol" and "physiological cooling agent," but of particular interest was the Court’s construction of "N-ethyl-p-methane-3-carboxamide."  Plaintiff/counter-defendant Wm. Wrigley Jr. Co.’s ("Wrigley") argued that the term in defendant/counter-plaintiff Cadbury Adams USA LLC’s ("Cadbury") patent should be required to be at least 30% of the cooling composition of the gum based upon alleged disclaimers in the specification, as well as alleged judicial and prosecution history estoppel.  The Court stated that it was a very close issue, but held that the term was not required to make up at least 30% of the cooling composition.  The specification language relied upon by Wrigley was in the preferred embodiment and, therefore, should not be read into the claims.  And while Cadbury may have disclaimed using less than 30% of N-ethyl-p-methane-3-carboxamide in the cooling compound during both the prosecution of other patents and judicial proceedings regarding those patents, the patents had no direct relation to the patent in suit and, therefore, estoppel could not apply.