A BE Study Comparing Mesalamine 400 mg to ASACOL® 400 mg in Patients With Mild To Moderately Active Ulcerative Colitis

Inclusion Criteria: Adults with newly diagnosed ulcerative colitis or with relapse following prior treatment and who met all the following criteria were eligible for participation in the study: 1. IRB approved consent form signed and dated prior to any study-related activities 2. Male or, if female, had undergone sterilization (hysterectomy or bilateral tubal ligation), was post-menopausal (defined as 1 year without menses) or has a negative pregnancy test at screening and, if heterosexually active, had used and agreed to continue to use: double-barrier method of contraception (condom and spermicide), oral or patch contraceptives, intrauterine device, or was in a monogamous relationship with a partner who had undergone a vasectomy. 3. 18 years of age or older 4. Newly diagnosed with ulcerative colitis or relapsed following prior treatment 5. Patient had not taken \> 1.6 g/day of mesalamine or equivalent for 14 days prior to randomization 6. Disease extending ≥ 15 cm above the anal verge on screening sigmoidoscopy or colonoscopy with confirming biopsy 7. Mild to moderate ulcerative colitis, defined as a Disease Activity Index (DAI) score between 4 and 9, inclusive, at study entry, and with a PGA of 1 or 2 and mucosal appearance (determined by endoscopy exam) score of 1 or 2 (mild/moderate) 8. Able and willing to have kept a daily diary during the study Exclusion Criteria: 1. Treatment with topical rectal, oral, or intravenous (IV) corticosteroids within 30 days of screening or immunosuppressives (e.g. azathioprine, 6-mercaptopurine) within the 90 days immediately preceding Screening 2. Use of rectal - administered aminosalicylates within 7 days of randomization 3. Patient had taken greater than 1.6 g/day of mesalamine or equivalent within 14 days of randomization 4. Crohn's disease, ischemic colitis, or disease of bacterial origin 5. Known allergy or hypersensitivity to aspirin or salicylate compounds 6. History of or laboratory results showing significant hepatic or renal disease or other significant medical condition which in the opinion of the investigator precluded participation in the study based on efficacy/safety assessments 7. History of cancer other than basal cell carcinoma within the five years immediately preceding study entry 8. In relapse for \> 3 weeks prior to the screening visit 9. Proctitis below 15 cm from the anal verge 10. History of or current gastrointestinal bleeding other than bloody stools associated with ulcerative colitis 11. History of bleeding disorder 12. Active peptic ulcer disease, history of gastrointestinal obstruction including severe constipation, or anatomic abnormality of the GI tract 13. Previous colonic surgery 14. History of alcohol or other substance abuse within the year immediately preceding anticipated study entry 15. HIV positive 16. \> 6 bloody stools per day 17. Positive stool culture for ova and/or parasites, enteric pathogens including Salmonella, Shigella, Yersinia, and Campylobacter, or positive stool assay for C. difficile toxin 18. Pregnant or breast feeding 19. Used an investigational drug in the 30 days prior to randomization 20. BUN or serum creatinine levels of 1.5 times the upper limit of normal (ULN) or liver enzyme levels \> 2 times the ULN