Contact Spermicides As Contraceptives : Efficacy And Current Status
Contact spermicides represent a novel method of contraception. Many compounds with diverse pharmacological activity have been evaluated in vitro for their spermicidal activity. Drugs with membrane stabilizing action such as procainamide, quinidine, mexiletine, propranolol, certain ionophores, chelating agents such as EDTA, gramicidin, natural or synthetic surfactants such as saponins, nonoxynol, benzalkonium chloride, anti-liquefying agents have all been demonstrated to possess good spermicidal activity. However, there is a paucity of data regarding the safety profile of most of these agents. In case of propranolol, chlorhexidine, gossypol and nonoxynol where such data is available, the results are not worthy enough to recommend their widespread use. Nonoxynol is the only contact spermicide currently being employed clinically. Combination formulations of two or more contact spermicides are being evaluated in order to minimize their adverse effects. But there is still a need to develop more safe contact spermicides.