Researchers have created a new easy-to-use intra-vaginal ring that could be extremely effective in preventing HIV in women. An anti-retroviral drug filled in the ring will enable it to avert the chances of AIDS.
The ring- known as TDF-IVR (tenofovir disoproxil fumarate intravaginal ring) has many advantages. It is easy-to-use and long lasting and has recently demonstrated a 100 per cent success rate in protecting primates from the simian immunodeficiency virus (SHIV). Researchers will soon test it on humans.
"After 10 years of work, we have created an intra-vaginal ring that can prevent against multiple HIV exposures over an extended period of time, with consistent prevention levels throughout the menstrual cycle," said Patrick Kiser, an expert in intra-vaginal drug delivery.
Antiviral drugs have proved to be effective in HIV prevention by previous studies 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 can be inserted easily and it stays in place for 30 days. It also utilises a smaller dose than pills because it is delivered at the site of transmission. 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, researchers said.
The ring has a unique polymer construction- its elastomer swells when the fluid is present, delivering up to 1,000 times more of the drug than current intra-vaginal ring technology, such as NuvaRing, which are made of silicon and have release rates that decline over time.
Other drugs could potentially be integrated into the ring, such as contraceptives or antiviral drugs to prevent other sexually transmitted infections - a feature that could increase user rates, said Kiser, who joined Northwestern University from the University of Utah, where the research was conducted.
The study was published in the journal Proceedings of the National Academy of Sciences (PNAS).
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