Developed with support from the National Institute of Allergy and Infectious Diseases by Northwestern University visiting associate professor Patrick Kiser, the ring is easy to use, long lasting, and recently demonstrated a 100 percent success rate protecting primates from the simian immunodeficiency virus (SHIV).
Kiser said that after 10 years of work, they have created an intravaginal ring that can prevent against multiple HIV exposures over an extended period of time, with consistent prevention levels throughout the menstrual cycle.
Previous studies have demonstrated that antiviral drugs can prevent HIV infection, but existing methods for delivering the drug fall short. Pills must be taken daily and require high doses; vaginal gels that must be applied prior to each sex act are inconvenient, yielding poor usage rates.
The new ring is easily inserted and stays in place for 30 days. And because it is delivered at the site of transmission, the ring - known as a TDF-IVR (tenofovir disoproxil fumarate intravaginal ring) - utilizes a smaller dose than pills.
The device contains powdered tenofovir, an anti-retroviral drug that is taken orally by 3.5 million HIV-infected people worldwide, but that has not previously been studied topically.
But the ring's strength stems from its unique polymer construction: its elastomer swells in the presence of fluid, delivering up to 1,000 times more of the drug than current intravaginal ring technology, such as NuvaRing, which are made of silicon and have release rates that decline over time.
The research has been published in the Proceedings of the National Academy of Sciences (PNAS).
--ANI (Posted on 28-09-2013)