The purpose of this study is to investigate the pharmacokinetics and pharmacodynamics of sitagliptin in healthy volunteers.

Inclusion Criteria:

• Healthy male subjects aged 20 - 50 years
• A body mass index (BMI) in the range 17-28 kg/m2
• Fasting plasma glucose levels in the range 70-110 mg/dL
• Sufficient ability to understand the nature of the study and any hazards of participating in it
• Provide written informed consent after being fully informed about the study procedures

Exclusion Criteria:

• Presence or history of severe adverse reaction to any drug (e.g., sitagliptin) or a history of severe allergic disease
• Clinically relevant abnormal medical history that could interfere with the objectives of the study
• A subject who has the following screening laboratory test results; creatinine clearance (calculated by Cockcroft-Gault equation) < 80 mL/min
• History of gastrointestinal disease or surgery (except simple appendectomy or repair of hernia), which can influence the absorption of the study drug
• A subject whose SBP is over 150 mmHg or below 100 mmHg and DBP is over 95 mmHg or below 65 mmHg
• Presence or history of drug abuse
• Participation in other clinical trial within 2 months
• Use of a prescription medicine, herbal medicine within 2 weeks or over-the-counter medication within 1 week before first dose
• Blood donation during 2 months or apheresis during 1 month before the study
• Presence or history of alcohol abuse
• Users of nicotine-containing substances within the previous three months
• Use of grapefruit juice, alcohol or smoking during restriction period
• Subject judged not eligible for study participation by investigator