Enhanced antibacterial activity of rifampicin associated with biodegradable polybutylcyanoacrylate nanoparticles

Association of rifampicin with polybutylcyanoacrylate nanoparticles provided considerable enhancement of drug antibacterial activity. In vitro nanoparticle-loaded rifampicin was more active against Staphylococcus aureus and Mycobacterium avium, localized in isolated alveolar macrophages. Level of rifampicin in macrophages increased 2-3-fold after incubation with rifampicin-loaded nanoparticles comparing to the free drug. High therapeutic efficacy of colloidal rifampicin was demonstrated in vivo. Use of nanoparticles provided 2-fold increase in rifampicin efficacy, comparing with the free drug at treatment of staphylococcus sepsis in mice. Single administration of nanoparticulate rifampicin in the dose 25 mg/kg resulted in 80% survival of mice with salmonellosis, while 50 mg/kg of free rifampicin could provide only 10% survival. It may be considered that high antibacterial efficacy of rifampicin bound to nanoparticles is due to its effective delivery to macrophages.