Vagina spermicides

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). 

Few, if any, products are administered via the vagina that are intended for systemic absorption. Thus, this route has not been as widely studied and characterized as others. On the other hand, large numbers of different products (douches, spermicides, antiyeast agents, etc.) have been developed that require introduction into the vagina in order to assert their localized effects. Increased research into different birth control and antiviral prophylaxis will result in more vaginal products in the future. All these must be assessed for vaginal irritation potential, and this serves as an example of the other tissue tolerance issues. 

Spermicides kill sperm. They are not completely effective as contraceptives when used alone but they improve the effectiveness of barrier methods. For centuries, women have used a variety of substances in conjunction with pads or sponges to prevent conception. Acids, such as vinegar, lemon juice and even Coca-Cola, restrict the motility of sperm, so that movement through the vagina is significantly restricted. 

Use of spermicides in the vagina (They are used in combination with barrier methods. This is strictly chemical rather than hormonal contraception as also are intrauterine devices that contain copper, which is gametocidal). 

The use of chlorhexidine in spermicides has been promoted as a strategy for protecting against sexually transmitted diseases, including HIV infection. However, both the claim of protection and the cytotoxicity of chlorhexidine, with a risk of damage to the epithelia of the vagina, cervix, and glans penis due to chronic exposure, have to be further validated (6). 

Spermicide—A substance (nonoxynol-9 in the United States) placed in the vagina to inhibit the activity of sperm, thus reducing the risk of pregnancy available as vaginal creams, films, foams, gels, suppositories, sponges, and tablets. 

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). 

The spermicide must be inserted into the female s vagina, not on the male s penis. 

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