The present invention relates to an antimicrobial composition for use in a method of delaying the onset of an infection or preventing an infection caused by a microbial organism in an internal cavity of a subject, wherein the antimicrobial composition comprises: an effective amount of an antimicrobial component comprising a cationic antiseptic selected from the group consisting of biguanides, bisbiguanides, polymeric biguanides, polymeric quaternary ammonium compounds, silver and its complexes, small molecule quaternary ammonium compounds selected from cetylpyridinium halides, and combinations thereof； wherein, if used, biguanides and bisbiguanides are present in the antimicrobial composition in an amount of at least 0.5 wt-%, based on the total weight of the antimicrobial composition； wherein, if used, polymeric quaternary ammonium compounds are present in the antimicrobial composition in an amount of at least 0.25% by weight, based on the total weight of the antimicrobial composition； wherein, if used, silver and its complexes are present in the antimicrobial composition in an amount of at least 0.20 wt-%, based on the total weight of the antimicrobial composition； wherein, if used, small molecule quaternary ammonium compounds are present in the antimicrobial composition in an amount of greater than 0.25 wt-%, based on the total weight of the antimicrobial composition； a hydrophilic component； and a surfactant component distinct from the antimicrobial component； with the proviso that when the internal cavity comprises a nasal passage, vagina, or oral cavity, the antimicrobial component does not include iodine or chlorhexidine； and wherein the antimicrobial composition is to be administered in a method comprising the steps of: contacting at least a portion of the interior surface of an opening leading to the internal cavity with an antimicrobial composition； and subsequently at least partially inserting an instrument into the opening.
