“Molecular condom” tested as preventive measure against HIV
Judit Fabian, University of Utah
Hydrogel is liquid at room temperature |
A vaginal gel, which can change to a liquid and release a drug during intercourse, has been designed by scientists in the US. It is hoped that the gel will eventually be used to prevent HIV infection.
The hydrogel, referred to as a molecular condom, is inserted as a liquid
at room temperature but at body temperature turns into a gel that is
retained in the vagina. When it subsequently comes into contact with
semen, it returns to liquid form — dependent on pH — and
a burst of entrapped drugs is released.
The gel is one of a number of microbicides, such as gels, rings, sponges
and creams, currently in development. Microbicides are seen as a way
for women to protect themselves from HIV and other sexually transmitted
infections, particularly in impoverished countries where HIV is widespread
and use of condoms is low. Until now, most microbicide work has concentrated
on development of the active drug and not on the delivery system.
Patrick Kiser, assistant professor of bioengineering at the University
of Utah, and colleagues tested the hydrogel delivery system under simulated
physiological conditions using a model drug. He hopes eventually to incorporate
entry inhibitors into the molecular condom. The microbicide currently
only lasts for a few hours but the researchers hope that this can be
extended to allow once daily or once monthly delivery.
“The promising drug release kinetics and erosion study results
… merits this drug delivery system, and systems like it, to be considered
as drug
delivery systems for the vaginal delivery of topical antivirals,” the
researchers conclude (published
online on 6 December 2006 in the Journal of
Pharmaceutical Sciences). |
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Pharmaceutical Journal
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