- Subjects whose second MDRD eGFR result on day -1 is not within 15% of the first eGFR result performed during the screening period. Healthy volunteers who have normal renal function, but show a difference greater than 15% in eGFR based on MDRD during the screening period, will be included in the trial at the discretion of the investigator and the sponsor after a 24-hour creatinine clearance has been performed that meets eligibility criteria.