Inclusion Criteria:

   1. Age ≥ 13 years and ≤ 75 years.

   2. Mild, moderate and severe ulcerative colitis (biopsy-proven)

   3. Mayo Scoring System Assessment of Ulcerative Colitis Activity score of 3 to 12 at
   screening.

   4. Patients with active disease who are refractory to, intolerant to, or unwilling to
   take 5-aminosalicylic acid (5-ASA).

   5. Patients of age ≥ 13 years and ≤ 17 years with active disease who are refractory or
   intolerant to 5-aminosalicyclic acid (5-ASA), corticosteroids, small molecule
   immunomodulators, and biologics or corticosteroid-dependent.

   6. Physician's Global Assessment (PGA) Mayo subscore of at least 1 at screening.

   7. Endoscopic evidence of active mucosal disease as assessed by flexible sigmoidoscopy
   with Mayo mucosal appearance subscore of at least 1 at screening.

   8. Female patients of child-bearing potential must have a negative serum pregnancy test
   at the screening visit and agree to use two medically reliable methods of
   contraception (such as barrier with either spermicide or hormonal contraception)
   during the study period.

   9. Male patients must be willing to use acceptable contraceptive methods and assure that
   their female partners of child-bearing potential use acceptable contraceptive methods
   during the study period.

10. Ability to adhere to the study visit schedule and other protocol requirements.

11. Adequate cardiac, renal, and hepatic function as determined by the principal
   investigators.

12. Written informed consent will be obtained before any study procedure is performed.

Exclusion Criteria:

   1. Are nursing or pregnant.

   2. Patients who are in critical condition

   3. Crohn's disease or indeterminate colitis.

   4. Known sensitivity to any ingredients in the study drug.

   5. A change in therapy within 2 weeks before the baseline visit.

   6. Use of immunomodulators (cyclosporine, mercaptopurine, azathioprine, etc.).

   7. Diagnosis of diabetes, heart failure, unstable angina, liver or kidney disease, or any
   other unstable medical condition.

   8. Any clinically meaningful laboratory abnormality that in the judgment of the
   investigator should preclude participation in the study.

   9. Impaired renal function (serum creatinine levels >2.0 mg/dL) at screening.

10. Alanine transaminase (ALT) or aspartate transaminase (AST) laboratory values >1.5
   times upper limit of normal at screening.

11. Diagnosis of Clostridium difficile, Salmonella, Shigella, Yersinia, Campylobacter,
   enteropathogenic E. coli in stool.

12. Positive test for hepatitis C virus (HCV) antibody or hepatitis B surface antigen
   (HBsAg) at screening.

13. Active malignancy (except basal cell carcinoma).

14. Active alcohol or drug abuse.

15. Tobacco smoking within 2 weeks before study entry.