American Journal of Drug Delivery

, Volume 4, Issue 1, pp 7–20

Potential use of vaginal rings for prevention of heterosexual transmission of HIV

A controlled-release strategy for HIV microbicides
  • A. David Woolfson
  • R. Karl Malcolm
  • Clare F. Toner
  • Ryan J. Morrow
  • Deborah Lowry
  • Asha Jamil
  • Stephen D. McCullagh
Leading Article


It is estimated that >80% of new HIV infections are contracted via heterosexual intercourse. Although a number of preventative strategies have been and are being pursued, the ultimate prevention tool–a safe, inexpensive, and effective vaccine–is nowhere on the horizon despite huge efforts over the past 2 decades. There is growing optimism that a vaginally applied HIV microbicide might be available for women to use within the next 5 years. It is likely that first-generation vaginal microbicides will make use of traditional semi-solid formulations since these are already used for vaginal administration of pharmaceutical substances. However, a number of drawbacks are associated with such formulations that may limit their clinical effectiveness as vaginal microbicide delivery vehicles.

In this article, the potential for providing controlled vaginal delivery of HIV microbicides using established vaginal ring technology is considered in detail for the first time. In particular, the article discusses and evaluates the pros and cons associated with prolonged continuous vaginal administration of HIV microbicides, reviews and compares the scientific literature with respect to user acceptability of vaginal semi-solids and rings, and then provides some in vitro data describing the zero-order controlled release of a number of lead candidate non-nucleoside reverse transcriptase inhibitors from silicone elastomer vaginal rings.


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Copyright information

© Adis Data Information BV 2006

Authors and Affiliations

  • A. David Woolfson
    • 1
  • R. Karl Malcolm
    • 1
  • Clare F. Toner
    • 1
  • Ryan J. Morrow
    • 1
  • Deborah Lowry
    • 1
  • Asha Jamil
    • 1
  • Stephen D. McCullagh
    • 1
  1. 1.School of PharmacyQueen’s University Belfast, Medical Biology CentreBelfastUK

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