As Pine suggests, interfering with hyaluronidase, the sperm enzyme that allows penetration of the outer ovum vestments, may be particularly appropriate. From his research in the 1940s, the concept of preventing sperm penetration of the ovum by enzyme inhibition has emerged. Considerable work has since been done. A good review is L.J.D. Zaneveld's article in Research Frontiers in Fertility Regulation, vol. 2, no. 3, pp. 1-14, 1982.
Present vaginal contraceptives use non-ionic surfactant compounds such as nonoxynol-9 as their active ingredient. No new active ingredients have been introduced for some years now, but several, such as Dpropranolol, are under development. The recent surge in litigation involving vaginal spermicides may force the manufacturers to remove nonoxynol-9 from the marketplace purely for economic reasons. This would be particularly troublesome not only because new compounds are several years away from the marketplace, but because contraceptives using nonoxynol-9 have been shown to reduce significantly ...
