BIOTEK proposes to investigate new bioprotective formulations which protect against sperm and STD pathogens by combining vaginal acidification with concentrations of nonoxynol-9 much lower, and potentially less irritating, than those used in current vaginal contraceptives. Such a combined spermicide-germicide should achieve widespread acceptance. Phase I will study vaginal gels designed to keep the pH between 2 and 3, and containing a few mg/ml of nonoxynol-9. Acidifying agents to be used include a strong sparingly soluble acid and a powerful acidic buffer. Extensive preliminary work by BIOTEK, using human semen and the FDA Testing Guidelines for Contraceptive Products, has shown that pH values of 2 to 3 may not disable sperm, but that introducing as little as l to 2 mg/ml of nonoxynol-9 to such an acidic preparation produces a fully spermicidal product. Phase I in vitro studies will include viscosity, viscous stability, equilibrium pH, and buffering capacity; in vivo studies will include vaginal irritation in rabbits and vaginal pH in sheep. Microbiological studies will be employed to test the effects on lactobacilli, human sperm, and important STD pathogens. Phase II will characterize a GMP gel, prepare and submit an IND, and proceed to an FDA-approved human clinical study.
A recent survey showed that, because of the risk of pregnancy and disease posed by partners who do not use condoms, women would welcome an unobtrusive vaginal product offering unilateral protection. A gel with both germicidal and spermicidal properties should tap into the existing market for vaginal contraceptives and facilitate development of vaginal gels for other indications.
