The federal-circuit affirmed the district court’s grant of a preliminary injunction preventing Hetero Labs from marketing a generic version of Otsuka’s Nuedexta drug, but vacated the district court’s order waiving the bond requirement under Federal Rule of Civil Procedure 65(c). Regarding claim construction, the court held that the terms “dextromethorphan” and “quinidine” in U.S. Patent No. 7,659,282 refer to the compounds as administered, including their salt forms (dextromethorphan hydrobromide and quinidine sulfate), rather than limiting the weight-to-weight ratio calculation to the active moiety components of those salts. The court applied de novo review for claim construction and clear error review for underlying factual findings, concluding that intrinsic evidence from the patent’s claims, specification, and prosecution history supported Otsuka’s interpretation that the ratio should be calculated based on the total weight of the administered salt forms. This construction rendered Hetero’s product within the scope of the patent’s 1:0.5 or less weight-to-weight ratio limitation, supporting a finding that Otsuka was likely to succeed on its infringement claim. On the procedural issue, the court applied Third Circuit law regarding Rule 65(c), which strictly interprets the bond requirement and permits waiver only under limited exceptions, such as when there is no risk of monetary loss to the defendant or in non-commercial cases involving important federal rights. The court determined that Hetero’s entry into the market with a generic pharmaceutical product constitutes a commercial, money-making activity, and the Third Circuit has never excused bond requirements in such contexts. Consequently, the court vacated the waiver of the bond requirement and remanded the issue to the district court for reconsideration of an appropriate security amount, noting that the patent’s expiration date is a relevant factor in determining the bond size.