Spermicidal agents

Diaphragms, shallow mbber cups with a flexible metal rim which are placed in the vagina and cover the cervix, are both a mechanical barrier to sperm and a receptable for spermicidal agent. The mechanism of action is beheved to be a combination of spermicidal and mechanical barrier actions. To be effective, the diaphragm must fit correctly, be inserted properly, and remain in place sufficiently long for the spermicide to act (99). 

Sperm agglutination antigen-1 MAb Tobacco Spermicidal agent... 

Lee, C. H., Bagdon, R. E., Bhatt, P. P, and Chien, Y. W. (1997), Development of silicone-based barrier devices for controlled delivery of spermicidal agents,/. Controlled Release, 44,43-53. 

Lactic acid is also used as a food preservative. Therapeutically, lactic acid is used in injections, in the form of lactate, as a source of bicarbonate for the treatment of metabolic acidosis as a spermicidal agent in pessaries for the treatment of leukorrhea in infant feeds and in topical formulations for the treatment of warts. 

The physical barriers include diaphragms and cervical caps made of rubber that fit in the vagina over the cervix. They are mechanical barriers to block the passage of sperm and are often used with spermicidal agents, such as nonoxynol (a surfactant 16.10). 

Twenty nine steroidal saponins have been evaluated for their inhibitory effects on human spermatozoa motility in vitro according to a modified Sander-Cramer method [233]. Spirostane-type saponins have stronger inhibitory activities than those of furostane-type. The carbonyl group at C-12 and the double bond A (5,6) of the aglycone were important for the activity. The monodesmosidic saponin, diuranthoside B from Diuranthera major appeared the most active (motility of 45% at 0.1 mg/ml), almost equivalent to the commonly used spermicidal agent N-9. These results indicated the possibility of discovering natural spermicidal agents from steroidal saponins. Further work on the cytotoxic activity of these compounds are underway. 

In the 1940s, at the Ortho research laboratories, the first spermicidal surfactants (octoxynol (Triton X-10(P) and nonoxynol-9 (Triton W )) were discovered and developed. Both of these substances became very quickly the leading spermicidal agents worldwide. Another product, a foaming tablet containing men-fegol from the Eisai company, followed in the late 1960s, but was introduced only in Europe. 

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