title: Intravaginal ring delivery of tenofovir disoproxil fumarate for prevention of HIV and herpes simplex virus infection.
abstract: OBJECTIVE
  A safe and effective topical prevention strategy will likely require sustained delivery of potent antiviral drugs and a delivery system that simultaneously maximizes drug distribution and overcomes the behavioural challenges related to adherence. Activity against HIV and herpes simplex virus (HSV) would be advantageous, given the epidemiological link between the two pathogens. We hypothesize that tenofovir disoproxil fumarate (tenofovir DF), a prodrug of tenofovir, may be more potent than tenofovir and ideal for sustained intravaginal ring (IVR) delivery.
  
  
  METHODS
  The anti-HIV and anti-HSV activity of tenofovir and tenofovir DF were assessed in cell and explant models. Cumulative tenofovir DF release and stability from polyether urethane (PEU), ethylene-co-vinyl acetate (EVA) and silicone IVRs were compared, and the activity and safety of drug released were evaluated in cervical explants and in a polarized dual-chamber model.
  
  
  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 μg/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.
  
  
  CONCLUSIONS
  The findings support the development of a PEU tenofovir DF ring, which may provide potent and sustained protection against HIV and HSV.
authors.affiliation: Department of Pediatrics and Microbiology-Immunology,  Albert Einstein College of Medicine, Bronx, NY,  USA.
authors.forename: Pedro M M
authors.initials: PM
authors.lastname: Mesquita
authors.forename: Rachna
authors.initials: R
authors.lastname: Rastogi
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Segarra
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Teller
authors.forename: N Merna
authors.initials: NM
authors.lastname: Torres
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Huber
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Kiser
authors.forename: Betsy C
authors.initials: BC
authors.lastname: Herold
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology*; D018929:Cell Culture Techniques; D018890:Chemoprevention / Q000379:methods; D003274:Contraceptive Devices, Female; D005260:Female; D006678:HIV / Q000187:drug effects*; D015658:HIV Infections / Q000517:prevention & control; D006558:Herpes Genitalis / Q000517:prevention & control; D006801:Humans; D009924:Organ Culture Techniques; D063065:Organophosphonates / Q000494:pharmacology*; D018139:Simplexvirus / Q000187:drug effects*; D000068698:Tenofovir
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine