New drug delivery vehicle to combat HIV

Scientists, led by an Indian-origin researcher, have developed a sensory tested drug delivery vehicle to protect women against sexually transmitted infections such as HIV during unprotected intercourse.
The method involves a semi-soft vaginal suppository made from the seaweed-derived food ingredient carrageenan and loaded with the antiviral drug Tenofovir.
With more than 34 million people worldwide living with HIV, microbicides - compounds that can be applied vaginally or rectally - offer a way to slow the spread of the virus, noted lead researcher Toral Zaveri, postdoctoral scholar in food science at Penn State University.
Containing agents known to prevent transmission of HIV and other viruses, microbicides can be inserted into the vagina prior to intercourse as a gel, cream, foam, sponge, suppository or film.

Zaveri pointed out that carrageenan was selected over gelatin - which traditionally has been used for semi-soft suppositories - because it offers a number of important advantages.
Because carrageenan is plant based, it is acceptable to vegetarians, there is no risk of animal-acquired infections and it avoids religious objections. Also, it is more stable than gelatin at higher ambient temperatures common in tropical regions of the world.

The suppositories developed by researchers hold particular promise for places such as regions of Africa, where HIV is widespread and women often are not in control of sexual situations, according to Zaveri.
"Condoms have been successful in preventing transmission of HIV and other sexually transmitted infections. However, effectiveness depends on correct and consistent use by the male partner," she said.

"Due to socioeconomic and gender inequities, women in some countries and cultures are not always in a position to negotiate regular condom use, so a drug-dispersing suppository can protect against transmission of HIV and other sexually transmitted infections during heterosexual intercourse with a partner whose infection status may or may not be known to the woman," Zaveri said.
As part of the research, Zaveri, who earned her doctorate in biomedical engineering at the University of Florida, conducted extensive sensory-perception testing to assess acceptability of the suppositories among women.
Women participating in the study were presented with suppositories - without the drug - in a variety of sizes, shapes and textures.

They indicated their preferences and rated the suppositories for willingness to try and imagined ease of insertion.