Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced the U.S. Food and Drug Administration (FDA) has accepted for Priority Review the Company's efficacy supplement to the New Drug Application (NDA) for XIFAXAN® (rifaximin) 550 mg tablets for the proposed indication of treatment of non–constipation irritable bowel syndrome (Non–C IBS) and IBS–related bloating. Non–constipation irritable bowel syndrome (Non–C IBS) encompasses two of the most common IBS subtypes: patients with diarrhea–predominant symptoms (IBS–D) and patients who suffer from intermittent periods of diarrhea and constipation known as mixed IBS (IBS–M).

A Priority Review classification is granted to drugs offering major advances in treatment, or providing a treatment where no adequate therapy exists. Based on this classification, the FDA has issued an action date of December 7, 2010 under the Prescription Drug User Fee Act (PDUFA).

"We are pleased with the FDA's acceptance of the sNDA for XIFAXAN550 and their decision to grant Priority Review for our application," said Bill Forbes, Pharm.D., Executive Vice President and Chief Development Officer, Salix Pharmaceuticals. "This review classification signals that the FDA considers that XIFAXAN550 may have the potential to provide a significant advance in the treatment of non–constipation irritable bowel syndrome. We believe the availability of XIFAXAN550 has the potential to change the treatment paradigm for Non–C IBS. Today's news marks a milestone for Salix, XIFAXAN550 and patients suffering from this widespread condition."