Antimicrobial compositions, especially those useful when applied topically, particularly to mucosal tissues (i.e., mucous membranes), including a cationic 
antiseptic such as biguanides and bisbiguanides such as 
chlorhexidine and its various salts including but not limited to the digluconate, diacetate, dimethosulfate, and dilactate salts; polymeric 
quaternary ammonium compounds such as polyhexamethylenebiguanide; silver and various silver complexes; 
small molecule quaternary ammonium compounds such as benzalkoium 
chloride and 
alkyl substituted derivatives; di-
long chain alkyl (C8-C18) 
quaternary ammonium compounds; 
cetylpyridinium halides and their derivatives; 
benzethonium chloride and its 
alkyl substituted derivatives; and octenidine. The compositions can also include an 
enhancer component, a surfactant, a hydrophobic component, and / or a hydrophilic component. Such compositions provide effective topical 
antimicrobial activity and are accordingly useful in the treatment and / or prevention of conditions that are caused, or aggravated by, microorganisms (including viruses).