Exhibit 99.1

FOR IMMEDIATE RELEASE

SALIX PHARMACEUTICALS ANNOUNCES FDA GRANTING OF

PRIORITY REVIEW DESIGNATION FOR THE CROFELEMER

NDA FOR TREATMENT OF DIARRHEA IN PATIENTS WITH

HIV/AIDS ON ANTI-RETROVIRAL THERAPY

PDUFA Action Date Designated as June 5, 2012

RALEIGH, NC, February 7, 2012 - Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced that the U.S. Food and Drug Administration (FDA) has granted Priority Review designation for the Company’s New Drug Application (NDA) for crofelemer 125 mg tablets for the proposed indication for the control and symptomatic relief of diarrhea in patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) on anti-retroviral therapy (ART).

The FDA grants a Priority Review designation to drugs offering major advances in treatment, or providing a treatment where no adequate therapy exists. Based on this review classification, the FDA has issued an action date for the NDA of June 5, 2012 under the Prescription Drug User Fee Act (PDUFA).

“We are pleased with the FDA’s acceptance of the NDA for crofelemer and their decision to grant Priority Review for our application,” stated Bill Forbes, Pharm.D., Executive Vice President, Medical, Research and Development, and Chief Development Officer, Salix. “This review classification signals that the FDA believes that crofelemer has the potential to provide a significant advance in the treatment of HIV/AIDS-associated diarrhea for patients on ART. We believe the availability of crofelemer has the potential to change the treatment paradigm for HIV/AIDS patients suffering from diarrhea.”

About Crofelemer

Crofelemer is a first-in-class, gastrointestinal agent of botanical origin. Crofelemer is a gut-targeted, orally administered, anti-secretory, anti-diarrheal agent that has minimal absorption. Crofelemer is a locally-acting product that is believed to possess dual novel mechanisms of action that might be effective in treating both acute infectious diarrhea and chronic diarrhea. Investigational studies support the use of crofelemer as an anti-secretory anti-diarrheal agent that may provide relief to patients through the inhibition of chloride secretion by both gut CFTR (Cystic Fibrosis Transmembrane Conductance Regulator Protein) as well as gut CaCC (calcium-activated chloride channel). Inhibiting CFTR and CaCC prevents the secretion of chloride and other ions, along with the water that passively follows chloride, out of the body into the intestinal lumen. This secretion leads to diarrhea, with the associated symptoms of dehydration, electrolyte imbalance, abdominal cramping, urgency and increased frequency. Additionally, crofelemer, unlike other anti-diarrheal agents, does not affect gut motility. In trials to date, crofelemer is well tolerated, and demonstrates a safety profile comparable to placebo. Crofelemer, if approved, would be a first-in-class CFTR inhibitor as well as a first-in-class CaCC inhibitor that would work as an anti-secretory anti-diarrheal drug.

About HIV/AIDS-Associated Diarrhea

Approximately 50% of the 1 million people in the United States living with HIV/AIDS are currently taking an anti-retroviral therapy (ART), and approximately 30% of HIV/AIDS patients on ART (approximately 150,000 patients) experience episodic or chronic diarrhea. Diarrhea in this patient population can result in weight loss, reduced quality of life, poor compliance with ART and increased healthcare costs.

Salix Pharmaceuticals, Ltd., headquartered in Raleigh, North Carolina, develops and markets prescription l products for the treatment of gastrointestinal diseases. Salix’s strategy is to in-license late-stage or marketed proprietary products, complete any required development and regulatory submission of these products, and market them through the Company’s gastroenterology specialty sales and marketing team.

Salix markets XIFAXAN^® (rifaximin) tablets 200 mg and 550 mg, MOVIPREP^® (PEG 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate and ascorbic acid for oral solution), OSMOPREP^® (sodium phosphate monobasic monohydrate, USP and sodium phosphate dibasic anhydrous, USP) Tablets, APRISO™ (mesalamine) extended–release capsules 0.375 g,), RELISTOR^® (methylnaltrexone bromide) Subcutaneous Injection, SOLESTA^®, DEFLUX^®, METOZOLV^® ODT (metoclopramide HCl, PEPCID^® (famotidine) for Oral Suspension, Oral Suspension DIURIL^® (Chlorothiazide), AZASAN^® (Azathioprine) Tablets, USP, 75/100 mg, ANUSOL–HC^® 2.5% (Hydrocortisone Cream, USP), ANUSOL–HC^® 25 mg Suppository (Hydrocortisone Acetate), PROCTOCORT^® Cream (Hydrocortisone Cream, USP) 1% and PROCTOCORT^® Suppository (Hydrocortisone Acetate Rectal Suppositories) 30 mg. Budesonide foam, RELISTOR^®, Lumacan^® and rifaximin for additional indications are under development.

For full prescribing information on Salix products, including BOXED WARNINGS for VISICOL, OSMOPREP and METOZOLV please visit www.salix.com or contact the Company at 919 862-1000.

Salix trades on the NASDAQ Global Select Market under the ticker symbol “SLXP.”

For more information please visit our web site at www.salix.com. Information on our web site is not incorporated in our SEC filings.

Please Note: The materials provided herein contain projections and other forward-looking statements regarding future events. Such statements are just predictions and are subject to risks and uncertainties that could cause the actual events or results to differ materially. These risks and uncertainties include, among others: the unpredictable nature of the duration and results of regulatory review of new drug applications; market acceptance for approved products; generic and other competition; the possible impairment of, or inability to obtain, intellectual property rights and the costs of obtaining such rights from third parties; and the need to acquire new products. The reader is referred to the documents that the Company files from time to time with the Securities and Exchange Commission.