Results: Tenofovir DF inhibited HIV and HSV at 100-fold lower concentrations than tenofovir and retained activity in the presence of semen. PEU rings delivered .1 mg/day of tenofovir DF for 30 days. Pre-treatment of cervical explants with 10 mg/mL tenofovir DF or eluants from PEU minirings resulted in .90% inhibition of HIV and reduced HSV-2 yields by 2.5 log. Tenofovir DF and eluants did not prevent cell growth or polarization,
or have any deleterious effects on an epithelial barrier.