Cumberland Pharms, Inc. v. Mylan Inst. LLC, No. 12 C 3846, Slip Op. (N.D. Ill. Feb. 26, 2014) (Pallmeyer, J.).

Judge Pallmeyer construed the claims in this patent infringement case involving an IV form N-acetylcysteine — used for treating acetaminophen overdoses.  Of particular note, the Court held as follows:

• “Free From A Chelating Agent & “Free Of A Chelating Agent” were defined as “lacking one or more chelating agents.”  “A” in these terms limited adding chelating agents, not the existence of any chelating agent.  This was supported by dependent claims which specified chelating agents.
• “Acetylcysteine” was defined as “the nonproprietary name for the N-acetyl derivative of the naturally occurring amino acid, L-cysteine (also known as N-acetyl-L-cysteine and NAC) and impurities associated therewith.”
• “Stable Aqueous Pharmaceutical Composition” was defined as “a composition that exhibits minimal change over time relative to when it is manufactured,” consistent with its plain meaning.