VAGINAL BIOPROTECTION BY CONTROLLED ACIDIFICATION

BIOTEK提议研究一种新的生物保护配方，通过将阴道酸化与壬氧醇醚-9的浓度结合起来，这种浓度比目前使用的阴道避孕药要低得多，而且可能刺激性更小，从而保护精子和性病病原体。这种杀精剂和杀菌剂的组合应该会得到广泛的接受。第一阶段将研究阴道凝胶，设计将pH值保持在2到3之间，并含有几毫克/毫升的壬氧醇-9。要使用的酸化剂包括强的稀溶酸和强酸性缓冲液。BIOTEK使用人类精液和FDA避孕产品测试指南进行的广泛初步研究表明，pH值为2至3可能不会使精子丧失功能，但在这种酸性制剂中加入1至2毫克/毫升的壬氧醇醚-9，就会产生完全杀精的产品。I期体外研究将包括粘度、粘度稳定性、平衡pH值和缓冲能力；体内研究将包括兔的阴道刺激和羊的阴道pH值。微生物学研究将用于测试对乳酸菌、人类精子和重要性病病原体的影响。II期将表征GMP凝胶，准备和提交IND，并进行fda批准的人体临床研究。拟议的商业应用：最近的一项调查显示，由于不使用避孕套的伴侣会带来怀孕和疾病的风险，妇女欢迎一种提供单方面保护的不显眼的阴道产品。一种同时具有杀菌和杀精性能的凝胶应该进入现有的阴道避孕药市场，并促进用于其他适应症的阴道凝胶的开发。

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. PROPOSED COMMERCIAL APPLICATIONS: 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.