BufferGel is a microbicidal spermicide that provides sufficient buffering activity to maintain the mild, protective acidity of the vagina in the presence of semen. Sperm are acid-sensitive, so to assure fertility, semen provides a powerful alkalinizing action that abolishes the protective acidity of the vagina for several hours after intercourse. This alkalinizing action of semen also enables acid-sensitive STD pathogens to transmit infection. By blocking this action of semen, BufferGel prevents unwanted pregnancy, and shows promise for prevention of STDs, including HIV/AIDS.
BufferGel’s additional attributes include:
- Colorless, tasteless, odorless
- Compatible with condoms and diaphragms
- Proven to be a safe, and effective contraceptive in Phase III trials
- Blocks HIV-infected cells, herpes, HPV, gonorrhea, and chlamydia in animal models
Unlike vaginal spermicides now on the market, BufferGel does not use detergents. It is a non-irritating lubricant gel formulation, based on a high molecular weight, cross-linked, buffering polymer. In addition, BufferGel is osmotically balanced with physiological salts. It contains no oils and is compatible for use with condoms and diaphragms.
Two Phase I clinical trials have been completed on the safety of BufferGel used vaginally by women of reproductive age who were HIV-negative, and either sexually-active, monogamous and at low risk for HIV, or abstinent. A U.S.-based trial was conducted in Providence, R.I. and an international trial was conducted at four sites: Pune, India; Chiang-Mai, Thailand; Blantyre, Malawi; and Harare, Zimbabwe. In both studies, BufferGel showed minimal toxicity and was well tolerated. The majority of participants said they would use the product if it were commercially available. In the international trial (which allowed women with bacterial vaginosis to enroll), the prevalence of bacterial vaginosis dropped significantly (by 80%) after one week of daily BufferGel. ,
BufferGel has recently completed two pivotal, registration-quality, Phase II/III contraceptive trials. The comparative trial was designed to test the non-inferiority of BufferGel to a marketed comparison spermicide, both used with a diaphragm, and this was achieved. In fact, the point estimates of pregnancy rates were lower for BufferGel than for Gynol II. The non-comparative trial confirmed the contraceptive efficacy of BufferGel-plus-diaphragm. The success of these trials is a critical milestone for BufferGel and for ReProtect and provide the data necessary to file an NDA for BufferGel used with a diaphragm as a contraceptive product.
ReProtect has developed a novel cervical barrier and applicator trademarked Duet™, a platform technology for delivery of vaginal microbicides, spermicides, and vaginal therapeutics. Duet will first be marketed with BufferGel, although it can be used with, and will likely increase the protective efficacy of any contraceptive or microbicide. Substantial research indicates that by protecting the cervix, contraceptive efficacy is enhanced, and that the cervix is one of the most vulnerable sites for STD transmission. Thus, combining a cervical barrier with a microbicide is a promising strategy to enhance protection against STDs including HIV/AIDS .
Duet’s attributes include:
- Easy insertion and removal
- Single size; therefore does not require a prescription, fitting, or a visit to a doctor
- Can be inserted well in advance of intercourse
- Novel shape applies microbicide to both the cervix and vagina
- Provides an additional layer of protection to increase the efficacy of any spermicide or microbicide
- Can be used to apply and retain diverse vaginal therapeutic products
- Inexpensive to manufacture
Duet is designed to provide the most reliable, and broad-spectrum protection achievable with microbicides, and do so with high convenience and acceptability and exceptionally low toxicity. Unlike conventional diaphragms, Duet requires no medical fitting or prescription, and is easier to insert and remove. Microbicide gel is applied to both sides of Duet, and its novel “sombrero” shape efficiently delivers and distributes the gel both to the cervix and to the vagina. Conventional diaphragms and caps deliver spermicide only to the surface of the cervix, leaving large surfaces of the vagina without protection. Duet delivers sufficient gel to these vaginal surfaces to protect them as well as provide 3 layers of protection for the cervix: vaginal-side gel, barrier film, and cervical-side gel.
Moench, Chipato and Padian, Preventing disease by protecting the cervix: the unexplored promise of internal vaginal barrier devices. 2001, AIDS 15