Contract research firm sues to patent stable antibiotic blend


Monday one the case has been filed in New Jersey District Court by Curia IP Holdings, LLC v Salix Pharmaceuticals, Bausch Health Companies and Alfasigma USA Inc. and their subsidiaries. The case concerns the infringement of the patents of Curia IP relating to a particular formulation of the antibiotic Rifaximin.

Curia, the complaint explained, is part of “a global contract research and manufacturing organization” that works with drug manufacturers on topics such as “drug discovery and candidate selection, development pharmaceuticals, analytical testing services, active pharmaceutical ingredient (“API”) development and manufacture, and pharmaceutical product development and manufacture in support of commercialization.

At issue in this case, Rifaximin, a broad spectrum antibiotic effective against various types of bacteria. However, the complaint explained that rifaximin is also sensitive to polymorphism, a phenomenon resulting in a variety of crystal forms for the compound, including α, β, gamma (“γ”), delta (“δ”) and epsilon ( “ε”) forms. In addition, the is likely to convert to the β format in the presence of moisture.

The applicant holds patents on a stabilized format of Rifaximin, which consists of a mixture of α and β type variations in a manner which prevents any further conversion or degradation of the types of Rifaximin, as well as ensuring a minimum percentage of type α, which is the clinically more effective variation.

The defendants are charged with selling the Rifaximin α single variation internationally and nationally. However, the α mixture is frequently exposed to sufficient moisture during the shipping process that it turns into the adjuvant patented by the applicants. The plaintiffs accuse the defendants of deliberately allowing this conversion in order to achieve patented stability without having to file an ANDA application or pay royalties to the plaintiff.

The plaintiffs are suing for patent infringement. They are represented by Lord Locke.


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