Safety Study of UC-781 Vaginal Microbicide

Inclusion Criteria for women: * Age 18-50 years old * Regular menses * HIV-1 seronegative at screening * Normal Pap smear at screening or documented normal Pap smear within six months prior to screening * No evidence of reproductive tract infection (RTI) * Willing and able to comply with study procedures, including pelvic exams, colposcopy, maintaining a study coital and symptom log, and applying assigned study gel per protocol * Agree to abstain from sexual intercourse for 24 hours prior to the enrollment visit * Agree to abstain from the following activities from at least 48 hours prior to enrollment through the Day 14 visit: * Insertion of fingers and other objects into the vagina * Receiving oral sex * Receiving anal sex * Using a diaphragm, cervical cap, female condom, or vaginal contraceptive ring * Using vaginal products other than the study gels, including douches, lubricants, or feminine hygiene products * In a monogamous sexually active relationship with one male partner * Report having vaginal intercourse only with that partner at least two times per week * No other reported partner in the prior six months and no plan to have another partner for the duration of the study * Agree to use condoms for each act of vaginal intercourse during participation in the study * Their male partner is informed and also consents to participate in the study * Willing to have male partner informed and treated if an STD is diagnosed at screening or during the study Inclusion Criteria for men: * Age 18 years or older * HIV-seronegative and free of other STI at screening exam * One female sexual partner; no other reported partner in the prior six months and no plan to have another partner for the duration of the study * Willing and able to comply with study procedures, including clinic visits, interviews and acceptability evaluation, and consistent use of condoms during enrollment in the study * Willing to have female partner informed and treated if an STD is diagnosed at screening or during the study Exclusion Criteria for women: * Pregnancy or desire to become pregnant at time of study participation * Currently breastfeeding * Delivery or abortion within last eight weeks * History of any male sexual partner other than current partner in past six months \- No abnormal (DAIDS grade 1 or higher) laboratory results at baseline, including hematology, liver and kidney function * History of post-coital vaginal bleeding in the past three months * History of surgery to remove uterus or cervix * History of surgery on the external genitalia, vaginal, or cervix in the past month * Clinically significant chronic medical condition that is considered progressive, including cardiopulmonary disease, renal disease, hepatic disease, diabetes mellitus. * History of sensitivity/allergy to latex * Existence of a clinically detectable genital abnormality at screening (e.g. ulcer, congenital abnormality, any lesion with mucosal disruption) * Concurrent participation in another trial of a vaginal product * Have any other condition that in the opinion of the investigator might interfere with the evaluation of the study objectives Exclusion Criteria for men: * History of genital surgery in the past month * Clinical or laboratory evidence of an STI. * History of sensitivity/allergy to latex * History of any sexual partner other than their current partner in the past six months