Five spermicides including nonoxynol-9 were assessed under in-vitro conditions, for their inhibitory activity against two viruses capable of spread by sexual intercourse, herpes simplex virus type-2 (HSV-2) and the human immunodeficiency virus type-1. A further eight commercially-available spermicidal preparations containing varying concentrations of either nonoxynol-9 or nonoxynol-11 were also assessed for activity against HSV-2. All spermicides and spermicidal preparations tested showed inhibitory activity against both viruses over periods of time ranging from 30 sec to 5 min. This activity was dependent on the concentration of spermicide to which the viruses were exposed.
PIP: In England, microbiologists at the University of Sheffield Medical School diluted herpes simplex virus-2 (HSV-2) in Eagle's Basal Medium + 5% fetal calf serum to a final concentration of 1 x 100,000 plaque-forming units/ml and HIV-1 in RPMI 1640 medium to a final concentration of 1 x 100,000 syncytium-forming units/ml. They wanted to study the inhibitory activity of the spermicidal agents nonoxynol-9, nonoxynol-11, benzalkonium chloride, menefegol, and sodium docusate. A concentration of pure nonoxynol-9 of .025% was the minimum concentration needed to inactivate HSV-2 in vitro, which was 4-160 time slower than concentrations of proprietary nonoxynol-9 preparations (2-8%) needed to have the same effect in vitro. The minimum concentration of nonoxynol-11 and benzalkonium chloride needed to inactivate HSV-2 in vitro was also .025%. Sodium docusate had a 2.5 times greater ability to inactivate HSV-2 in vitro than did nonoxynol-9 and nonoxynol-11 and benzalkonium chloride (minimum concentration = .01%). The minimum concentration of menfegol needed to inactivate HSV-2 in vitro was lower than that of the other spermicidal agents (.1%, a concentration 4 times lower than that of nonoxynol-9). All the spermicidal agents effective at inactivating HSV-2 did so in at least 30 seconds. The minimum concentration of nonoxynol-9 needed to maximally inactivate HIV-1 in vitro was .025%. it did so in 30 seconds. The lowest concentration of sodium docusate, menfegol, and benzalkonium chloride necessary for in vitro HIV-1 inactivation was also .025% (minimum time: 30 seconds for the first 2 spermicides and 2.5 minutes for the third). These findings suggest that spermicidal agents have virucidal capabilities.