This is a single-center, open-label, single-dose evaluation of 1 mg UT-15C SR pharmacokinetics, safety, and tolerability in subjects with normal, mild, moderate and end stage renal disease (ESRD; on dialysis).

Subjects in the ESRD group will receive 2 doses of UT-15C SR, separated by 14 days. One dose will be given 4 hours prior to dialysis, the other dose will be given at the end of dialysis.

Pharmacokinetic samples will be taken immediately prior to dosing and 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 24, 30, 36, 42 and 48 hours post dose. Additionally, subjects with ESRD will have a sample taken at 60 hrs post dose.

Male and female volunteers with ESRD (requiring dialysis), moderate (creatinine clearance; CrCL = 30-50 mL/min), mild (CrCL = 50-80 mL/min) and normal renal function (control group; (CrCL >80 mL/min)) may be enrolled. Eligible subject will be 18-79 years of age with a BMI between 18 - 40 kg/m2 and not taking chronic nonsteroidal antiinflammatory drugs (NSAIDs)