Primary Objective: To assess the effect of the coadministration of multiple dose of CJ-12420 and clarithromycin on the pharmacokinetics (PK) of CJ-12420 or clarithromycin.

Secondary Objective(s): To assess the safety of the coadministration of multiple dose of CJ-12420 and clarithromycin in healthy subjects

An open-label, randomized, 6-sequence, 3-period, 3-treatment crossover design

Inclusion Criteria:

• Healthy male volunteers in the age between 19 and 45 years old
• Body mass index(BMI) in the range of 19 to 28 kg/m2
• Understand the requirement of the study and voluntarily consent to paticipate in the study

Exclusion Criteria:

• History of clinically significant medical history or disease (hepatic, kidney, gastrointestinal,respiratory, musculoskeletal, endocrine,neuro-psychiatric, haemato-oncologic,urinary tract, cardiac arrhythmia and cardiovascular system) judged by investigator.
• Clinically significant abnormal laboratory results within at least 28 days prior to the first day of drug administration. AST or ALT > 1.25 times of upper limit value Total bilirubin > 1.5 times of upper limit value estimated GFR :less than 80 mL/min
• Clinically significant abnormal ECG results within at least 28 days prior to the first day of drug administration PR ≥ 210 msec QRS ≥ 120 msec QT ≥ 500 msec QTcF ≥ 500 msec
• Clinically significant hypersensitivity reaction against investigational drug or other drugs
• history of drug abuse or "positive" results from drug screening test.
• Take medicine such as prescription medicine or herbal medicine, over-the-counter drug, vitamin supplements
• Person who have intake history of food or drug which can affect drug absorption, drug distribution, drug metabolism, and drug excretion and bowel activity
• Volunteer have a history of donation of whole blood donation, apheresis, transfusion
• Volunteer a heavy drinker(30g/day), smoker(10 cigarettes/day), heavy caffeine consumer(400mg/day)