Effectiveness of BufferGel as a Vaginal Contraceptive

Vaginal acidity is thought to be one means by which the vagina prevents overgrowth or colonization by harmful microbial flora. Sperm and many STD pathogens, including HSV-1 and HSV-2, Neisseria gonorrhoeae, Treponema pallidum, Haemophilus ducreyi, and a variety of bacterial vaginosis-associated bacteria, are inactivated at pH less than 5 in vitro. BufferGel, a vaginal spermicide and microbicide, is an acidic buffer that maintains the vagina at or near its natural state of mild acidity. Formulated at vaginal pH (pH 3.9), BufferGel prevents or limits the semen-induced rise in vaginal pH. Carbopol 974P, the buffering agent in BufferGel, is a high molecular weight, cross-linked, polyacrylic acid used as a gelling or tableting agent in many pharmaceuticals; it has a well-documented record of mucosal safety in animals and humans. This study will determine the safety and contraceptive efficacy of BufferGel spermicide used with a diaphragm compared to Gynol II spermicide used with a diaphragm. The study will also measure the frequency of bacterial vaginosis, urinary tract infections, and cervical lesions in women using BufferGel compared with Gynol II. Participants in this study will be fitted for a diaphragm and randomized to receive either BufferGel or Gynol II. All participants will be instructed on the use of the test product with the diaphragm. Participants will be followed through 6 menstrual cycles (approximately 7 months) and will have 4 study visits and one study phone call. Some participants may enroll in an extended version of the study and be followed for an additional 6 cycles and 2 additional study visits. Study visits will include a gynecologic exam, Pap smear, and blood and urine tests. Participants will be asked to keep a diary to record information on product use. Some participants may also be asked to enroll in a colposcopy substudy. These participants will undergo colposcopy at study entry and after cycles 1, 3 and 6.