When it comes to preventing infection with HIV, women have very few options, and those that are available are frequently not practical. Yet heterosexual intercourse is the method by which more than 80% of HIV-infected women are exposed to the disease. Topical antiretroviral medications used prior to intercourse that can prevent infection have suffered from difficulties in administration or logistics. A new way to prevent HIV infection in women—using a peudo-tampon—is now being studied.
Cameron Ball and Kim A. Woodrow of the University of Washington published their paper on the tampon-like device online ahead of print in Antimicrobial Agents and Chemotherapy. The device is created by weaving the antiretroviral maraviroc into water-soluble nano fibers. These electrospun fibers are about 200 times thinner than a strand of human hair. After insertion into the vagina, the fibers can dissolve and release an effective dose of the antiretroviral in about six minutes. The authors envision that intercourse could then further disperse the drug throughout the vagina.
This new method of self-administration, either with fingers or with an applicator, could help solve several problems inherent with other antiretroviral formulations. Compliance may be low with gels, because patients find them messy. Films and tablets containing antiretrovirals can take up to 15 minutes to dissolve. If the material is not fully dissolved, it can become an abrasive and result in damage to the walls of the vagina and an increased risk of infection. The tampon may be easier to use than these other formulations, increasing compliance rates and offering another choice to at-risk women.
While preventing infection with HIV is the first potential use for these fibers, the study authors foresee other applications. The quick-dissolving fibers of the tampon might also be used to carry contraceptives or drugs used to prevent STDs.
The antiretroviral tampon is also not without its challenges, however. One problem is that women most at risk for infection with HIV may not use conventional tampons, which could result in lowered compliance. Further, the antiretrovirals studied are still in clinical trials, meaning that it could take 10 years to bring the pseudo-tampon to the mass market. The authors of the research are aware of these difficulties and are experimenting with different applicators that may make administration easier.
Ball C, Woodrow K. Electrospun Solid Dispersions of Maraviroc for Rapid Intravaginal Preexposure Prophylaxis of HIV. Antimicrob Agents Chemother. 2014 Aug;58(8):4855-4865. doi: 10.1128/AAC.02564-14. Epub 2014 Jun 9. Available at: http://www.ncbi.nlm.nih.gov/pubmed/24913168?dopt=Abstract