A Drug-drug Interaction Study to Evaluate the Effect of Rifampicin and Febuxostat on the Pharmacokinetics of Methotrexate in Healthy Subjects

Inclusion Criteria: * Age between 19 to 50, healthy male subjects (at screening) * Body weight between 50.0 kg - 90.0 kg, BMI between 18.0 - 30.0 kg/m2 * Subject who totally understand the progress of this clinical trials, make decision by his free will, and signed a consent form to follow the progress Exclusion Criteria: * Subject who has a past or present history of any diseases (eg. liver, kidney, neurology, immunology, pulmonary, endocrine, hematology, oncology, cardiology, mental disorder) * Subject who had GI tract disease (Crohn's disease, ulcer, acute or chronic pancreatitis) or surgery (appendectomy, hernioplasty are excluded) * Serum AST(SGOT), ALT(SGPT), total bilirubin \>1.5 times upper limit of normal range, MDRD eGFR \< 60mL/min/1.73m2, WBC count \< 3,500 /uL, SBP \< 90 mmHg or \> 150 mmHg, DBP \< 50 mmHg or \>100 mmHg * Subject who had galactose intolerance, Lapplactase deficiency or glucose-galactose malabsorption * Subject who had received drugs inhibiting or inducing metabolic enzymes/transporters such as barbiturates, statins, digoxin in 3 months * Subject who had taken St.John's wort and food including grapefruit in 2 weeks * Smoking in 3 months * Subject who had whole blood donation in 2 months, or component blood donation in 1 month or transfusion in 1 month currently