Cellulose sulfate microbicide safe and acceptable to HIV-positive women

This article is more than 18 years old. Click here for more recent articles on this topic

An experimental topical gel designed to avoid the transmission of HIV and sexually transmitted infections is safe to use and acceptable to HIV-positive women and their HIV-positive male partners, according to a double-blind placebo controlled trial published in the May edition of AIDS. The gel, which includes cellulose sulfate will now be examined in further, larger studies.

Microbicide gels may offer women a means of protecting their own sexual and reproductive health without relying on the use of condoms by their male partners. Cellulose sulfate is an antifertility gel the antimicrobial properties of which have been demonstrated in laboratory studies. It has been shown to be safe and well-tolerated when used in topical vaginal gels in HIV-negative women and men.

There have been few studies looking at the safety and acceptability of vaginal microbicides in HIV-positive women; therefore researchers from the US designed a double-blind randomised control trial involving 59 HIV-positive women. They were randomly given a gel containing 6% cellulose sulfate or a placebo consisting of KY gel. Both products looked and smelled the same. The study had four arms: two consisted of sexually abstinent women who were asked to apply their assigned gel once or twice daily; the other two arms comprised sexually active women who were told to apply their gel once daily (up to two hours prior to sexual intercourse), or twice daily. All the women were asked to record their use of the gel, the frequency of sexual intercourse, any side-effects and the general acceptability of the gel both to them and their sexual partner.



A pill or liquid which looks and tastes exactly like a real drug, but contains no active substance.


A product (such as a gel or cream) that is being tested in HIV prevention research. It could be applied topically to genital surfaces to prevent or reduce the transmission of HIV during sexual intercourse. Microbicides might also take other forms, including films, suppositories, and slow-releasing sponges or vaginal rings.


Applied directly to the affected area, as opposed to systemic. For example, a cream or lotion, applied to body surfaces such as the skin or mucous membranes inside the vagina or rectum.



A clinical trial where neither the researchers nor participants know which assigned treatment an individual participant in the trial is taking until after the end of the trial. This reduces the risk of biased results. 

randomised controlled trial (RCT)

The most reliable type of clinical trial. In a trial comparing drug A with drug B, patients are split into two groups, with one group receiving drug A and the other drug B. After a number of weeks or months, the outcomes of each group are compared.

In all, 62% of women who were assigned to the cellulose sulfate arm and 70% of women in the placebo arm reported some form of side-effect. None were serious or life-threatening, the most frequent being mild urogenital symptoms, such as abdominal or pelvic pain or genital itching. There was no significant difference between the likelihood of side-effects occurring or the type of side-effects according to the use of cellulose sulfate or placebo or the frequency of its application.

None of the women experienced any significant laboratory abnormalities as a consequence of using the gel. Adherence was comparable between the women assigned to cellulose sulfate (69%) and those provided with the placebo (71%). Adherence was higher amongst sexually active women.

Almost all (96%) users of the cellulose sulfate gel said that they would probably or definitely use it if it was available.

“This study demonstrated that cellulose sulfate gel is a suitable candidate for continued development as a vaginal microbicide”, conclude the investigators, adding “the demonstration of its safety and acceptability to HIV-infected individuals is important in its planning for further assessment in clinical trials with larger numbers of participants.”


El-Sadr WM et al. Safety and acceptability of cellulose sulfate as a vaginal microbicide in HIV-infected women. AIDS 20: 1109-1116, 2006.