This study is aimed to evaluate the pharmacokinetics and the drug-drug interaction among anti-hypertension drugs-amlodipine, losartan, and hydrochlorothiazide. This pilot study provides useful information to develop a new fixed dose combination drug.

Inclusion Criteria:

• Adult subjects 20-50 years of age
• Above 55Kg and within ±20% ideal body weight
• Subjects who are in average of 130mmHg ≤ systolic blood pressure (SBP) < 160mmHg, 80mmHg ≤ diastolic blood pressure (DBP) < 100mmHg
• Female subject who confirmed non-pregnant status and agree to comply with proper contraception.
• Subjects who wrote informed consent

Exclusion Criteria:

• Subjects who are suspected to have acute disease
• Subjects who have past history that may affect drug absorption, distribution, metabolism and elimination
• Subjects who have gastrointestinal history
• Subjects whose heartrate is less than 60
• Subject who suspected to orthostatic hypotension
• Subjects who have clinically significant allergy disease
• Subject is currently participating or has participating in a study with an investigational compound or device within 30 days of signing informed consent
• Administration of prescription drug within 14 days or over the counter (OTC) drug within 7 days
• Subjects who have past history of drug abuse and positive in drug screening test
• Subjects who donate whole blood within 60 days and platelet within 30days.
• Subjects taking St John's wort or CYP inhibitor and inducer