Dry powder PA-824 aerosols for treatment of tuberculosis in guinea pigs.

Abstract

Novel treatments for multidrug-resistant tuberculosis (MDR-TB), extensively drug-resistant tuberculosis (XDR-TB), or latent TB are needed urgently. Recently, we reported the formulation and characterization of the nitroimidazo-oxazine PA-824 for efficient aerosol delivery as dry powder porous particles and the subsequent disposition in guinea pigs after pulmonary administration. The objective of the present study was to evaluate the effects of these PA-824 therapeutic aerosols on the extent of TB infection in the low-inoculum aerosol infection guinea pig model. Four weeks after infection by the pulmonary route, animals received daily treatment for 4 weeks of either a high or a low dose of PA-824 dry powder aerosol. Animals received PA-824 cyclodextrin/lecithin suspensions orally as positive controls, and those receiving placebo particles or no treatment were negative controls. The lungs and spleens of animals receiving the high dose of inhaled PA-824 particles exhibited a lower degree of inflammation (indicated by wet tissue weights), bacterial burden, and tissue damage (indicated by histopathology) than those of untreated or placebo animals. Treatment with oral PA-824 cyclodextrin/lecithin suspension resulted in a more significant reduction in the bacterial burden of lungs and spleen, consistent with a dose that was larger than inhaled doses (eight times the inhaled low dose and four times the inhaled high dose). However, histopathological analysis revealed that the extent of tissue damage was comparable in groups receiving the oral or either inhaled dose. The present studies indicate the potential use of PA-824 dry powder aerosols in the treatment of TB.

• Authors: Lucila Garcia-Contreras, Jean C Sung, Pavan Muttil, Danielle Padilla, Martin Telko, Jarod L Verberkmoes, Katharina J Elbert, Anthony J Hickey, David A Edwards
• Journal: Antimicrobial agents and chemotherapy (Antimicrob Agents Chemother) Vol. 54 Issue 4 Pg. 1436-42 (Apr 2010) ISSN: 1098-6596 [Electronic] United States
• PMID: 20086154 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Aerosols
• Antitubercular Agents
• Nitroimidazoles
• Powders
• pretomanid

Topics

• Administration, Inhalation
• Administration, Oral
• Aerosols
• Animals
• Antitubercular Agents (administration & dosage, blood)
• Chemistry, Pharmaceutical (methods)
• Colony Count, Microbial
• Disease Models, Animal
• Extensively Drug-Resistant Tuberculosis (drug therapy)
• Guinea Pigs
• Humans
• Latent Tuberculosis (drug therapy)
• Lung (microbiology, pathology)
• Male
• Nitroimidazoles (administration & dosage, blood)
• Particle Size
• Powders
• Spleen (microbiology, pathology)
• Tuberculosis, Multidrug-Resistant (drug therapy)
• Tuberculosis, Pulmonary (blood, drug therapy, microbiology, pathology)