RALEIGH, N.C. — Salix Pharmaceuticals Ltd. has been issued three patents for Xifaxan (rifaximin), an antibiotic for the intestinal tract, from the U.S. Patent and Trademark Office.
The company said Wednesday that one of the patents (U.S. Patent No. 7,928,115), granted this week, provides protection to methods of treating travelers’ diarrhea (TD) with rifaximin. The patent provides protection for the TD indication for the rifaximin 200 mg product that Salix markets in the United States under the name Xifaxan.
Salix was issued the other two rifaximin patents in March. One (U.S. Patent No. 7,906,542) provides protection relating to pharmaceutical compositions comprising rifaximin in polymorphic forms, while the other (U.S. Patent No. 7,902,206) provides protection relating to rifaximin in polymorphic form alpha-free from other polymorphic forms of rifaximin not derived from form alpha by water absorption or release, according to the company.
Salix said it has an exclusive license to the ‘542 and ‘206 patents from Alfa Wassermann to use, sell, have sold and import licensed rifaximin products, which the company markets in the United States under the names Xifaxan (200 mg) and Xifaxan 550 (550 mg).
A gut-selective antibiotic, rifaximin passes through the stomach and into the intestines without being absorbed into the bloodstream. The medication is used to treat travelers’ diarrhea caused by E. coli in adults and children who are at least 12 years old.
According to Salix, Alfa Wassermann has marketed rifaximin in Italy under the name Normix for over 30 years. Salix acquired rights to market rifaximin in North America from Alfa Wassermann.
