In vitro activity of benzoxonium chloride on selected buccopharyngeal pathogens.

Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of N-benzyl, N-dodecyl-N,N-di(2-hydroxyethyl)ammonium chloride (benzoxonium chloride, Orofar), a quaternary ammonium salt, were assayed on 14 strains associated with buccopharyngeal infections. MICs ranged between 2-5 micrograms/ml for Gram-positive bacteria and between 16 and 48 micrograms/ml for Gram-negative organisms. For Candida albicans they were between 6-8 micrograms/ml. MBCs for 1 and 2 min were only slightly higher than MICs. One strain of K. pneumoniae required, however, 100 micrograms/ml and 10 min of exposure. Results show that benzoxonium chloride has strong antimicrobial effect on organisms responsible for buccopharyngeal infections.