Dual purpose contraceptives: targeting fertility and sexually transmitted disease

There have been no radically new forms of contraception since the pill was introduced 1960 and even this form of fertility regulation can be traced back to endocrine advances that were made in the 1920s. Whatever new forms of fertility control we introduce for the future, they should exploit the significant advances that have been made in our understanding of the reproductive system in recent years and be tailored to the needs of the 21st century. In this context, there is an urgent need to develop novel, safe, effective, dual-purpose contraceptive agents that combine the prevention of pregnancy with protection against sexually transmitted diseases (STDs). To achieve this aim we have researched a class of a topical contraceptive agent that selectively and instantaneously immobilizes millions of spermatozoa, while suppressing the infectivity of pathogenic microbes, such as Chlamydia, in the ejaculate. This approach is based upon the ability of small molecular mass organic compounds to selectively and covalently adduct key proteins in spermatozoa and pathogenic organisms and disrupt their biological function. We have also successfully developed strategies for the preparation of latent formulations that would only become activated on contact with seminal plasma. The further development and refinement of these molecules should permit a radical rethink in the way that safe, effective topical protection is provided to control both fertility and the world-wide spread of STDs.