Bioavailability of Amoxicillin Dissolved in Human Milk

The investigators propose to study amoxicillin absorption in a 2-stage program that will progressively produce, for the first time, information leading to pediatric pharmacology recommendations for the administration to children of amoxicillin dissolved in human milk. The investigators study will enroll adult volunteers as number of blood extractions, volume of blood required and subject availability, among other issues, generate a number of ethical and logistical constraints that make it almost impossible to carry such an intensive sampling study in infants.

As recommended by the Expert Committee on Selection and Use of Essential Medicines, WHO (http://www.who.int/selection_medicines/committees/en/index.html), oral solid formulations are the preferred forms of medicines for children, especially in developing countries, because of relatively inexpensive and less complicated manufacturing, transporting and storage processes. Whereas solid dosage forms are advantageous in these pharmaceutical logistics, administering solid formulations to infants and children is a challenging issue. Dissolving medicines in water may be acceptable, but safety of drinking water for infants in developing countries and water solubility of the drug itself are major concerns. These challenges are exemplified in the treatment of infectious diseases and diarrhea in infants. Commonly used drugs for infants in low income settings include antibiotics such as amoxicillin. Expert sources have suggested that drug administration in breast milk may be effective. However, little data is currently available to support the recommendation to administer medications dissolved in breast milk to infants.

The second stage of the project will use the information obtained from the first stage, combined with pre-existing data, to define a rational dosing schedule of the target drug dissolved in human milk for young children, using population PK modeling and simulation. This is a study in silico.

Eligibility Criteria:
Inclusion Criteria:

1. Healthy adult volunteers (\>18 and \<60 years old)
2. An approximate 50% of the volunteers will be female
3. Body mass index (BMI) within 18.5 to 29.9 kg/m2
4. Healthy according to medical history, vital signs and a brief physical examination as determined by the principal investigator/Sub-investigators.
5. Systolic blood pressure between 100-140 mmHg, inclusive and diastolic blood pressure between 60-90 mmHg, inclusive, and heart rate between 50-100 bpm, unless deemed not clinically significant by the principal investigator/Sub- investigators.
6. Capable of giving written informed consent prior to receiving study medication
7. Smoking is not an exclusion criterion but we will identify smokers.
8. Female participants will be required to fulfill at least one of the following:

   * Agree to avoid pregnancy and use medically acceptable method of contraception from at least 30 days prior to the study, during the study, and until 30 days after to the study has ended (last study procedure). Medically acceptable methods of contraception include hormonal patch, implant or injection intrauterine device, or double barrier method (condom with foam or vaginal spermicidal suppository, diaphragm with spermicidal). Complete abstinence alone can be used as a method of contraception. Oral contraceptives prior to the study are acceptable as a method of contraception, but an alternative method of contraception will be required during the study and after the study has ended.
   * Be surgically sterile for a minimum of 6 months
   * Post menopausal for a minimum of 1 year.

Exclusion Criteria:

1. Known history of any clinically significant hepatic (e.g. hepatic necrosis, jaundice, hepatobiliary disease), renal, gastrointestinal (e.g. peptic ulcer), cardiovascular (e.g. angina, myocardial infarction), cerebrovascular, pulmonary, endocrine (e.g. diabetes, hypophosphatemia), immunological, musculoskeletal (e.g. rhabdomyolysis, myopathy), neurological, psychiatric, dermatological, or haematological disease or condition
2. History of any clinically significant illness within 30 days prior to dosing
3. History of any significant physical or organ abnormality
4. Known history of:

   * Alcohol abuse or dependence within one year prior to drug administration
   * Drug abuse or dependence
   * Food allergies and/or presence of any dietary restrictions
   * Severe allergic reactions (e.g. anaphylactic reactions, angioedema)
5. Participation in another clinical trial or receiving an investigational drug within 30 days of the study commencement or during the study
6. Use of any prescription medication within 14 days prior to drug administration (except for hormonal contraceptives)
7. Use of any over the counter medications )including herbal and/or dietary supplements and/or teas) within 24 hrs prior to drug administration (except for spermicidal/barrier contraceptive products)
8. Any major surgery within 6 months prior to the start of the study
9. History of allergy to amoxicillin, beta-lactams or amoxicillin excipients
10. History of allergy to milk, or severe lactose intolerance
11. Pregnancy or lactating
12. Conditions associated with malabsorption
13. Taking any form of antacids as they may increase the risk of orally transmitted viruses from human milk.