Pharmacokinetic Study of the Vaginal Microbicide Agent 1% Tenofovir Gel

Inclusion Criteria:

• Must be between 18-45 years old, inclusive
• Must be in general good health by volunteer history without any clinically significant systemic disease (including liver disease/hepatitis, gastrointestinal disease, kidney disease, thyroid disease, osteoporosis or bone disease)
• Must have regular menstrual cycles (minimum of 26 and maximum of 38 days)
• Must be at least 2 months since last pregnancy outcome and have had at least two spontaneous menses
• Must abstain from sexual activity and use of intravaginal products for 72 hours prior to the start of the single-dose phase and multi-dose phase, for at least one week following vaginal biopsies and for the duration of the study phases
• Willingness to give voluntary consent, sign an informed consent form and comply with study procedures as required by the protocol

Exclusion Criteria:

• Currently pregnant or at risk for pregnancy (may be using Paragard® IUD, effective barrier method, female sterilization or abstinence, or be sexually active with a vasectomized partner)
• Currently breastfeeding or planning to breastfeed during the course of the study
• Use of any hormonal contraceptives within 30 days of enrollment
• Use of Depo-Provera within 120 days of enrollment History of abnormal Pap smear (by volunteer history) that has not been evaluated and treated, if indicated, according to standard guidelines
• Current vaginal or urinary tract infection
• Positive test for Neisseria gonorrhea or Chlamydia trachomatis at the time of screening
• Positive wet mount for Trichomonas vaginalis at the time of screening or enrollment
• Deep epithelial genital findings such as abrasions, ulcerations, and lacerations, or vesicles suspicious for a sexually transmitted infection
• Current or past use of any anti-retroviral therapies including but not limited to systemic tenofovir (Viread®)
• Current or recent drug or alcohol abuse
• Current or anticipated use of drugs on a daily basis that may reduce renal function (e.g. acyclovir or ibuprofen) or liver function (e.g. tylenol)
• HIV positive at the time of screening
• Hepatitis B surface antigen (HBsAg) positive at the time of screening
• Grade 1 or higher serum chemistry or complete blood count abnormality in accordance with DAIDS toxicity table values
• Abnormal finding on laboratory or physical examination or a medical condition which, in the opinion of the investigator, would make participation in the study unsafe or would complicate interpretation of data
• Participation in any other research study in the 30 days prior to screening and/or plans to participate in any other research study during entire study duration