Study to Evaluate the Incidence of Gastric Ulcers Following Administration of Either PA32540 or Enteric Coated Aspirin 325 mg in Subjects Who Are at Risk for Developing Aspirin-Associated Ulcers

Exclusion Criteria

• •1. Baseline endoscopy showing any gastric, esophageal or duodenal ulcer at least 3 mm in diameter with depth
• •2. Positive test result for H. pylori at screening 3A. Have had a revascularization procedure (i.e., Coronary Artery Bypass Graft, Percutaneous Transluminal Coronary Angioplasty, or carotid endarterectomy) less than six months prior to screening
• •4\. Unstable hypertension as judged by the Investigator 5. Uncontrolled diabetes mellitus as judged by the Investigator 6. Unstable cardio- or cerebrovascular disease such that it would endanger the subject if they participated in the trial 7. Clinically significant valvular disease 8. Congestive heart failure or other cardiovascular symptoms according to New York Heart Association (NYHA) Functional Classification III or IV (Appendix 3) 9. History of hypersensitivity to omeprazole or to another proton pump inhibitor 10. History of allergic reaction or intolerance to aspirin and/or a history of aspirin-induced symptoms of asthma, rhinitis, and/or nasal polyps 11. History of serious UGI event, such as bleeding, perforation, or obstruction 12. Gastrointestinal disorder or surgery leading to impaired drug absorption 13. Presence of chronic or uncontrolled acute medical illness, e.g. gastrointestinal disorder (esophageal stricture, severe esophagitis, long-segment Barrett's esophagus, signs and symptoms of gastric outlet obstruction), thyroid disorder and/or infection that would endanger a subject if they were to participate in the study 14. Schizophrenia, uncontrolled bipolar disorder, or severe depression 15. History of alcoholism or drug addiction within a year prior to enrollment in the study 16. Severe hepatic dysfunction (i.e. cirrhosis or portal hypertension) 17. Blood coagulation disorder, including use of systemic anticoagulants such as warfarin or other vitamin K antagonists 18. Any condition that, in the opinion of the Investigator, may either put the subject at risk or influence the results of the study 19. Use of any excluded concomitant medication (see Section 9.2) 20. Screening laboratory ALT or AST value \> two times the upper limit of normal 21A. History of renal insufficiency 22. Other than noted specifically, any screening laboratory value that is clinically significant in the Investigator's opinion and would endanger a subject if the subject was to participate in the study 23. Use of an investigational treatment in the 4 weeks before screening 24. History of malignancy, treated or untreated, within the past five years, with the exception of successfully treated basal cell or squamous cell carcinoma of the skin 25. Previous participation in another PA32540 clinical research study 26. Subjects, who are employees of the research facility, immediately related to the Principal Investigator, or are in some way under the supervision of the Principal Investigator.