Antimicrobial Activity, In Vitro, of Chlorhexidine*

Comparative in vitro tests indicate that chlorhexidine has greater antibacterial activity than benzalkonium chloride, a combination of o-phenyl- and p-tert-amyl-phenol, and an iodine-polyvinylpyrrolidone complex under the test conditions. Chlorhexidine in relatively high dilutions was effective against several cultures of Gram-negative bacteria in the phenol coefficient test. In moderate concentrations, it was active against staphylococci and anaerobes.