New Delivery Methods for Antivirals Discussed

SAN DIEGO —  A vaginal silicone ring that delivers molecules that act on both HIV and herpes virus may present a way for preventing HIV infection in young women at high risk of exposure, according to research presented at the 55^th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC/ICC).

“We succeeded in creating a ring that can deliver hydrophilic molecules such as tenofovir, active on HIV-1, and acyclovir, active on herpes virus, despite the fact that silicone is a hydrophobic compound,” Meriam Memmi, author of the study and PhD candidate at University Jean Monnet of Saint-Etienne, France said in a press release. This was possible due to the addition of a hydrophilic compound to the silicone, which allowed the drugs to be released from their reservoirs.

Vaginal rings with multiple reservoirs present a promising way for preventing sexually transmitted infections (STIs) and notably HIV infection in young women with high risk of exposure, according to Memmi and colleagues. 

Some of the rings presented in this study were shown to release concentrations of drugs between 1.5 and 3.5 mg/day for acyclovir and 3 to 5 mg/day for tenofovir for as long as 50 days, which corresponds to doses capable of preventing viral sexual-transmitted infections such as HIV-1 infection, hepatitis B and genital herpes.

These preliminary results demonstrate the ability of silicone rings to continuously deliver hydrophilic antiviral drugs for a long period of time at a concentration that would be effective for neutralizing the viruses present in semen. The process is intended to be evaluated in clinical trials and to be industrialized with the goal of producing rings at high rate and low cost.

Reference

1. Memmi M. Silicone vaginal rings to deliver antiviral drugs, protect women against HIV. Presented at: ICAAC/ICC 2015; Sept. 17-21, 2015; San Diego.