Researchers@EVMS

Brief description: This prospective, double-blinded, randomized, parallel cohort study will examine the genital and systemic safety, pharmacokinetics (PK), pharmacodynamics (PD), disintegration and disappearance times, and acceptability of four vaginal tablets: 1) Tenofovir (TFV) alone; 2) Emtricitabine (FTC) alone; 3) TFV combined with FTC; and 4) placebo. Participants will be randomized to treatment group, to number of tablets to be inserted in the Single Use Phase (1 tablet or 1 tablet followed by a second tablet two hours later to mimic the BAT24 dosing regimen), and to one of four collection time points (2, 4, 6, or 24 hours after tablet insertion) for assessments only after the last dose of the Multiple Use Phase. In the Single Use Phase of the study, the participant will insert one tablet in the clinic to estimate times to disintegration and disappearance. Those randomized to two tablets will insert a second tablet 2 hours later. In all women, sample collection will occur 5 hours after the initial tablet insertion. In the Multiple Use Phase of the study, participants will insert a tablet once daily for 14 days. The 1st, 7th, and 14th tablets will be inserted in the clinic; the remaining tablets will be inserted at home. The clinic will call the participant on day 3 of the multiple use phase to ask about any symptoms the participant may be experiencing. Each insertion in the clinic will be followed by sample collection and, at Visits 4 and 6, colposcopy at the participant's assigned time point.

Detailed description: Objectives: Primary: To assess genital safety after a single use (consisting of one tablet in half of participants and one tablet followed by a second tablet two hours later in the other half) and during and after two weeks of daily tablet use To assess systemic safety after two weeks of daily tablet use To assess the pharmacokinetics (PK) of TFV and FTC after a single use (as defined above) and during and after two weeks of daily tablet use Secondary: To estimate the time needed for tablet disintegration and the time needed for full tablet disappearance To assess acceptability of the tablet To assess indicators of the pharmacodynamics (PD) of TFV and FTC in vitro using biological samples (fluids) from study participants obtained before use, after a single (use as define above), and after two weeks of daily tablet use Exploratory: •To assess exploratory indicators of the PD of TFV and FTC in vitro using biological samples (tissues) from study participants obtained before use, after a single use (as defined above), and after two weeks of daily tablet use