The purpose of this study is to compare the pharmacokinetics and pharmacodynamics of CJ-12420 after single and multiple dose administration according to H. pylori infection.

1. Cohort 1: To investigate the pharmacokinetics and pharmacodynamics of CJ-12420 after the multiple dose administration in H. pylori negative volunteers.
2. Cohort 2: To investigate the pharmacokinetics and pharmacodynamics of CJ-12420 after the single dose administration in H. pylori positive volunteers.

Inclusion Criteria:

• Healthy male volunteers between 20 to 45 years of age (inclusive)

• Body mass index (BMI) in the range of 19~28 kg/㎡ and weighted at least 50kg

• Medically healthy with no clinically significant vital signs (blood pressure in the sitting position, pulse rate)

  • 90 mmHg ≤ systolic blood pressure ≤ 140 mmHg
  • 50 mmHg ≤ diastolic blood pressure ≤ 95 mmHg
  • 45 beats per minute ≤ pulse rate ≤ 95 beats per minute

• Understood the requirements of the study and voluntarily consented to participate in the study

• Agreed to be sexually abstinent or to use a condom or spermicide when engaging in sexual activity and not to donate sperm during the course of the study for 30 days following completion of the study

• Non-smokers or non-users of nicotine-containing products for at least 1 year

• [Cohort 1] H. pylori negative as determined by urea breath test and serum IgG antibody

• [Cohort 2] H. pylori positive as determined by urea breath test and serum IgG

Exclusion Criteria:

• History of clinically significant gastrointestinal, renal, hepatic, neurologic, hemato-oncologic, endocrine, pulmonary, immunologic, psychiatric, musculoskeletal, or cardiovascular disease or any other condition, which in the opinion of the investigators, would jeopardize the safety of the subject or impact the validity of the study results
• History of allergy or hypersensitivity to any drug, including prior serious adverse reaction to PPIs or P-CABs
• Undergone surgery or in a medical condition, which in the judgment of the PI or investigators may affect absorption, distribution, metabolism or elimination of the study drug
• Administered other drug(s) in other clinical study within 60 days prior to screening visit
• Donated blood within 60 days or blood components within 30 days, or had been transfused plasma within 30 days prior to screening visit
• On special diet or have experienced substantial changes in eating habits within 30 days prior to screening visit
• Used any prescription medication within 14 days, or any other OTC medications including herbal products within 7 days prior to screening visit
• Consumed over 21 units/week of alcohol
• Consumed over 5 units/day of caffeine-containing beverage
• Positive urine screen for drugs and/or cotinine
• Positive blood screen for human immunodeficiency virus (HIV), hepatitis B or C, or syphilis
• Clinically significant abnormalities of liver function tests (≥1.5 fold of normal upper limit in the level of L-alanine aminotransferase (ALT), L-aspartate aminotransferase (AST) or total bilirubin)
• Unable to bear pH meter catheter insertion
• History of symptomatic GERD, erosive esophagitis, duodenal ulcer, gastric ulcer, Barrett's esophagus, or Zollinger-Ellison syndrome
• Clinically significant observations considered as unsuitable based on medical judgment by investigators