The goal of the proposed studies is to provide a formulation of C31G based agents into a vaginal contraceptive of high effectiveness together with the ability to: 1) provide rapid delivery of C31G after a single application, 2) provide long-acting spermicidal and microbicidal activity after a single application, 3) protect the user against AIDS (HIV) and other STDs, 4) protect vaginal and cervical epithelia from irritation, 5) enhance penetration of spermicide into cervical mucus, 6) demonstrate low systemic bioavailability and, finally 7) be pharmaceutically and cosmetically acceptable.