Efficacy and Safety Study of HZT-501 in Subjects Requiring Nonsteroidal Anti-Inflammatory Drug (NSAID) Treatment

Inclusion Criteria: * Expected to require daily administration of an NSAID for at least the coming six months for conditions such as osteoarthritis, rheumatoid arthritis, chronic low back pain, chronic regional pain syndrome, and chronic soft tissue pain. * Did not use a NSAID within the 30 days prior to study entry Exclusion Criteria: * History of erosive esophagitis * History of any of the following serious gastrointestinal complications: * perforation of ulcers, * gastric outlet obstruction due to ulcers, or * gastrointestinal bleeding. * Active cardiac, renal, and/or hepatic disease * Current Helicobacter pylori (H. pylori) infection * Use of an acid suppressant agent, misoprostol, or more than 325 mg/day of aspirin within the 14 days prior to study entry. * Uncontrolled diabetes * Uncontrolled hypertension * Positive pregnancy test at screening * Positive test at Screening for human immunodeficiency virus (HIV), hepatitis B, or hepatitis C. * Currently participating, or participation within 30 days prior to study entry, in an investigational drug study Please note that there are other additional criteria. The study center will determine if patients meet all of the criteria.