Navigation Links
Reduced glycerin formulation of tenofovir vaginal gel safe for rectal use

PITTSBURGH, May 17, 2012 A change in the formulation of tenofovir gel, an anti-HIV gel developed for vaginal use, may make it safer to use in the rectum, suggests a study published online this week in the Journal of Antimicrobial Chemotherapy. In laboratory tests of rectal tissue, researchers from the Microbicide Trials Network (MTN) found that the reformulated gel was less harmful to the lining of the rectum than the original vaginal formulation, and just as effective in protecting cells against HIV.

"The lining of the rectum is much more fragile than the vaginal epithelium, so we can't be certain a product like tenofovir gel that is safe for vaginal use will be completely safe to use in the rectum," said lead study author Charlene Dezzutti, Ph.D., associate professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine and principal investigator of the MTN Network Laboratory. "We are very encouraged by our laboratory data that suggest the reformulated gel could be safer for rectal use, and serve as a dual compartment gel for use in both the vagina and rectum."

Tenofovir gel has shown some promise in reducing HIV risk in women through vaginal sex. But because the rectal epithelium the lining of the rectum that serves as the first line of defense against HIV is much thinner than the vaginal lining, the gel may not be safe or effective to use rectally. Indeed, unprotected anal sex is 10 to 20 times more likely to result in HIV infection than unprotected vaginal intercourse. By its nature, tenofovir gel is hyperosmolar contains a higher concentration of sugars and salts relative to cells. This quality could have a harmful effect on the rectal lining by causing epithelial cells to shrink as they purge water to achieve balance. Weakened in this manner, the rectal epithelium may be less able to protect against HIV.

To make tenofovir gel safe and more amenable to rectal use, researchers from CONRAD, a research organization which holds the rights to develop the gel, reformulated it with a reduced amount of glycerin, a common additive found in many gel-like products. In laboratory tests conducted by MTN researchers, the reformulated gel was three times less likely to cause cells in rectal tissue to release water, and equally effective against HIV as the vaginal formulation.

Data from an early phase clinical trial of the reduced glycerin gel presented in March 2012 at the 19th Conference on Retroviruses and Opportunistic Infections (CROI), suggested it was safe and acceptable in 65 HIV-negative men and women who used it rectally once a day for one week. Results from this study, called MTN-007, and future studies will have important implications for the development of a rectal microbicide that could help protect against HIV or other sexually transmitted infections during anal sex.

As follow-up to MTN-007, researchers are now planning a Phase II, multi-site trial called MTN-017 that will involve 186 men who have sex with men, and transgender women at clinical sites in Peru, South Africa, Thailand, and the U.S. Participants will cycle through three study regimens: reduced glycerin tenofovir gel used daily, reduced glycerin tenofovir gel used before and after anal sex, and daily use of the antiretroviral tablet Truvada. MTN-017 will allow researchers to collect additional information

In addition to Dr. Dezzutti, other authors of the study are Lisa Rohan, Ph.D., University of Pittsburgh; Lin Wang, M.D., Ph.D., Magee-Womens Research Institute ; Kevin Uranker, Magee-Womens Research Institute; Cory Shetler, Magee-Womens Research Institute; Marilyn Cost, Magee-Womens Research Institute; J.D. Lynam, Magee-Womens Research Institute; and David Friend, Ph.D., CONRAD, Arlington, Va.

Tenofovir gel contains the antiretroviral tenofovir, which is commonly used in the treatment of HIV. The vaginal formulation of tenofovir gel was found safe and effective in reducing the risk of HIV in women who used it before and after vaginal sex in a study called CAPRISA 004. More recently, however, MTN researchers conducting the VOICE Study closed the tenofovir gel arm of the trial after a routine review of study data determined that the gel, while safe, was not effective in preventing HIV among the women in that study group, who were asked to apply it vaginally every day. In the meantime, a Phase III trial called FACTS 001 is currently evaluating the vaginal formulation of tenofovir gel using the same regimen as CAPRISA 004, with results expected in 2014.


Contact: Clare Collins
Microbicide Trials Network

Related biology news :

1. How the ecological risks of extended bioenergy production can be reduced
2. Study: Quebec ban on fast-food ads reduced consumption of junk food
3. New fermented soy ingredient containing S-equol significantly reduced hot flash frequency
4. Reduced bone density, stunted growth in turtles exposed to common chemical
5. Gene regulatory protein is reduced in bipolar disorder
6. Aquarium fishes are more aggressive in reduced environments, a new study finds
7. Vitamin D deficiency associated with reduced lung function
8. Identifying factors in atrazines reduced weed control
9. Combination therapy reduced HER2-positive breast cancers
10. More than 1,000 tigers reduced to skin and bones in last decade
11. Chefs can create reduced-calorie restaurant foods
Post Your Comments:
(Date:11/19/2015)... YORK , Nov. 19, 2015  Although some ... market is dominated by a few companies, according to ... companies own 51% of the market share of the ... The World Market for Molecular Diagnostic s ... "The market is still controlled by one company ...
(Date:11/17/2015)...  Vigilant Solutions announces today that Mr. Dick ... --> --> Mr. ... partnership at TPG Capital, one of the largest global ... in revenue.  He founded and led TPG,s Operating Group, ... from 1997 to 2013.  In his first role, he ...
(Date:11/12/2015)... 2015   Growing need for low-cost, easy ... been paving the way for use of biochemical ... analytes in clinical, agricultural, environmental, food and defense ... in medical applications, however, their adoption is increasing ... continuous emphasis on improving product quality and growing ...
Breaking Biology News(10 mins):
(Date:11/28/2015)... ... November 28, 2015 , ... • Jeon Jin Bio ... porcine and rodent control solutions , Bird ... oil, works across all sensory modalities including visual, smell, taste and touch, enabling safe, ...
(Date:11/27/2015)... November 27, 2015 ... popularity of companion diagnostics is one of ... market with pharmaceutical companies and diagnostic manufacturers ... tests. . --> ... report on global cancer biomarkers market spread ...
(Date:11/25/2015)... 2015 --> ... - 2020 report analyzes that automating biobanking workflow ... in long-term samples, minimizing manual errors, improving the ... manual errors such as mislabeling or inaccurate sample ... plays a vital role in blood fractionation, DNA ...
(Date:11/25/2015)... , November 25, 2015 ... cat and human plaque and pave the way for more ... problems in cats     --> ... most commonly diagnosed health problems in cats, yet relatively little ... now. Two collaborative studies have been conducted by researchers from ...
Breaking Biology Technology: