Inclusion Criteria:

• Subject must have endoscopically confirmed erosive esophagitis as defined by the Los Angeles (LA) Classification Grading System (A-D).

Exclusion Criteria:

• Evidence of uncontrolled, clinically significant systemic disease; acquired immunodeficiency syndrome (AIDs); a condition likely to require surgery; cancer within 5 years of screening; or abnormal laboratory values.
• Co-existing diseases affecting the esophagus; history of esophageal radiation therapy, cryotherapy, or physiochemical trauma.
• History of esophageal surgery or dilatation of an esophageal stricture other than Schatzki's ring; gastric or duodenal surgery except simple oversew of an ulcer.
• Active gastric or duodenal ulcers or acute upper gastrointestinal hemorrhage within 30 days prior to screening.
• Current or history of Zollinger-Ellison syndrome or other hypersecretory conditions.
• Allergy to any proton pump inhibitor drug (omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole), any component of Ilaprazole, or antacid.
• Unable to tolerate lactose.
• Use of the following medications prior to randomization or anticipated use during the study: proton pump inhibitors, antacids, biphosphonates, histamine (H2) receptor antagonist (examples: Zantac, Tagamet), sucralfate, misoprostol, corticosteroids, prokinetics, Non-steroidal anti-inflammatory drugs (NSAIDs), strong anticholinergics, anticoagulant/anti-platelet aggregate therapy, anticoagulants, digoxin, theophylline, phenytoin.
• History of alcoholism or drug addiction.