Patient description: A 67-year-old healthy woman came to the clinic to have her flu shot in early October. She works at a rehab center and has no underlying disease. It is her first vaccination this year. she is menopausal and has 4 children. She does not some. She takes daily multivitamins and anti-hypertensive drugs. She exercises regularly for 30 minutes a day at least 5 days a week. She has no allergies to any food or drugs.

Clinical trial eligibility criteria: eligible ages (years): 18.0-64.0,  Healthy Is the individual a healthy, normal adult man and woman who volunteers to participate? ls s/he at least 18 years of age? Is his/her BMI between 19 and 30, inclusive? Is she willing .to avoid pregnancy by abstaining from sexual intercourse with a non-sterile male partner, or by the use one of the following methods: diaphragm + spermicide or condom + spermicide (at least 14 days before dosing), intra uterine contraceptive device or hormonal contraceptives (at least 4 weeks prior to dosing), or has she been surgically sterile or post-menopausal at least six months prior to entering into the stndy? Is s/he considered .reliable and capable of understanding his/her responsibility and role in the study Has s/he provided written informed consent? A no answer to any of the above questions indicated that the individual was ineligible for enrollment  Does the individual have a history of allergy or hypersensitivity to amlodipine? Does s/he have clinically significant laboratory abnormalities that would interfere with the conduct or interpretation of the study or jeopardize his/her safety? Does s/he have significant history or clinical evidence of auto-immune, cardiovascular, gastrointestinal, hematological, hematopoietic, hepatic, neurological, ongoing infection, pancreatic, or renal diseases that would interfere with the conduct or interpretation of the study or jeopardize his/her safety'? Is she nursing? Does s/he have serious psychological illness? Does s/he have significant h/story (within the past year) or clinical evidence of alcohol or drug abuse? • Does s/he have a positive urine drug screen or a positive HIV-1, or hepatitis B or C screen, or a positive pregnancy test? Has s/he consumed grapefruit or grapefruit juice during the 7rday period preceding study initiation? Is s/he unable to refrain from the use of alcohol or xanthine-containing foods or beverages during periods beginning 48 hours prior to study drug administration and ending when the last blood sample has been taken in each study period? Has s/he used any prescription drug, other than hormonal contraceptives, during the 14-day period prior to study initiation, or any OTC drug during the 72-hour period preceding study initiation? Is s/he unable to refrain from the use of all concomitant medications, other than hormonal contraceptives, during the study? Has s/he donated or lost blood, or participated in a clinical study which involved the withdrawal of a large volume of blood (480 mL or more), during the six week period preceding study initiation? Has s/he donated plasma during the two week period preceding study initiation? Has s/he received an investigational drug during the 30 day period preceding study initiation? Is s/he a heavy smoker (usually smoking more than 10 cigarettes per day)?