Vaginal contraception

In the last several decades, physical properties of vaginal contraceptive formulations have been improved to deUver spermicide more effectively and enhance consumer compliance. The formulation that deUvers the spermicide can affect the efficacy of vaginal contraceptives (86,87). Formulations currentiy available include jeUies, creams, suppositories, aerosol foams, and foaming tablets. Each consists of a relative inert base material that serves as a carrier for the chemically active spermicide and blocks to some extent the passage of sperm. 

The vaginal contraceptive sponge (Today) contains 1 g of nonoxynol-9 and provides protection for 24 hours. After intercourse, the sponge must be left in place for at least 6 hours before removal, ft is available without a prescription. 

Doncel, G. F. Chemical vaginal contraceptives Preclinical evaluation, in Barrier Contraceptives Current Status and Future Prospects, Mauck, C., Cordero, M., Gabelnick, J. L., Spieler, J. M., and Rivera, R. (Eds), pp. 147-162, WUey-Liss, New York, 1994. 

Cesari et al. (2007) demonstrated on bovine and human sperm in vitro that potato aspartic proteases 1 and 3 are effective spermicidal compounds. Spermicidal activity is due to membrane permeabilization and is not related to the proteolytic activity. Cesari et al. (2007) suggest vaginal contraception as a possible applieation. 

There has been a resurgence of interest in vaginal contraception methods as a result of recent concerns about the prolonged use of oral combined contraception. The issue of compliance is also a major stumbling block for the contraceptive pill. Although the theoretical effectiveness of the pill is close to 100%, various studies have demonstrated that the real life pregnancy rate is almost 8 per 100 women during their first year of use [154,155],... 

C. L. Joyce and L. J. D. Zaneveld. Vaginal contraceptive activity of hyuluronidsse and cyckroaiygenase (prostaglandin synthetase) inhibitors in (he rabbit. Fert. Ster. 44 426 (1985). 

D. Duncan, G. Fabrication and testing of vaginal contraceptive devices designed for release of prespecified dose levels of steroids. Contraception 1978, 17, 221-230. 

Meyer U, Gerhard I, Runnebaum B. Benzalkonium-chlorid zur vaginaten Kontrazeption—der Scheidenschwamm. [Benzalkonium chloride for vaginal contraception—the... 

Toxic shock syndrome has also been described in association with use of a vaginal contraceptive sponge vaginal cultures grew S. aureus (10). 

Faich G, Pearson K, Fleming D, Sobel S, Anello C. Toxic shock syndrome and the vaginal contraceptive sponge. JAMA 1986 255(2) 216-18. 

Phenylmercuric nitrate is also an effective spermicide, although its use in vaginal contraceptives is no longer recommended see Section 14. 

Fahim MS, Wang M. Zinc acetate and lyophilized Aloe barbadensis as vaginal contraceptive. Contraception 1996 53 231-236. 

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