This study aims to investigate the pharmacokinetics/pharmacodynamics metformin IR after oral administration in healthy elderly male volunteers.

Inclusion Criteria:

• Males aged 65-85 years with a body mass index (BMI) of 18-28 kg/m2
• Good health based on complete medical history, physical examinations, vital signs, electrocardiography (ECG), and clinical laboratory evaluations including hematology (blood cell count, hemoglobin, and platelet count), liver function test (aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin), serum creatinine, blood glucose and urinalysis

Exclusion Criteria:

• If they had clinically relevant disorders
• Past history of diabetes or clinical findings to suspect diabetes
• Abnormal clinical laboratory values (i.e., platelets ≤ 75,000/mm3, hemoglobin ≤ 9 g/dL, neutrophils absolute ≤ 1000/mm3, fasting glucose > 126mg/dL, creatinine ≥ 1.5 mg/dL, or AST, ALT > 3 × upper limit of normal)