Comparison of antimicrobial effect of free and liposomal amikacin against Pseudomonas aeruginosa

Pseudomonas aeruginosa is important opportunistic pathogen and to produce widespread infection by numerous virulence factors. Drug delivery system that reduces the drugs toxicity while increasing their therapeutic index is a great interest and liposomes can provide the benefits. Liposomes are colloidal vesicules ranging from a few nanometers to several micrometers in diameter. The present invitro study was designated to evaluate the antimicrobial activity of free and liposomal amikacin against Pseudomonas aeruginosa (ATCC 27853). The minimal inhibitory concentrations (MICs) of free and liposomal amikacin for Pseudomonas aeruginosa (ATCC 27853) were determined by broth macro-dilution technique as recommended by CLSI (Clinical and laboratory standards institute). We therefore, encapsulated this drug in to liposome prepared by sonication. Change of number of bacteria in equal minimal inhibitory concentration of liposomal amikacin was compared with the change of number of bacteria in the present of variousconcentrations of free amikacin. The results showed that of liposomal amikacin had antimicrobial effect and MIC of liposomal amikacin were equal of 4μg/ml however minimal inhibitory concentration of free amikacin was 2μg/ml.Comparison of change of number of bacteria had shown that the effect of liposomal amikacin (4 μg/ml) after 8 h is equal of 6 μg/ml free amikacin after 4h. According to the results we can probably to use of liposomal amikacin for Pseudomonas infections, but we need more study and research.