Liposome-encapsulated cephalothin in the treatment of experimental murine salmonellosis

The effectiveness of liposome-encapsulated cephalothin was compared with free cephalothin for the treatment of mice experimentally infected with Salmonella typhimurium. Compared with free cephalothin, following intravenous administration, liposome-encapsulated cephalothin was cleared from the circulation more rapidly and concentrated in the liver and spleen. Treatment of infected mice with the liposome antibiotic complex was more efficacious in terms of reducing the number of S. typhimurium in these organs as compared with the free antibiotic. The results suggest that liposome-encapsulated antimicrobial agents may possess a therapeutic advantage in the treatment of diseases caused by facultative intracellular bacteria since this manipulation favors delivery of the entrapped antibiotic to intracellular sites occupied by S. typhimurium.