The influence of surface active l-leucine and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) in the improvement of aerosolization of pyrazinamide and moxifloxacin co-spray dried powders

Pharmacotherapy of tuberculosis is potentially more efficient when delivered by the inhaled route than by the current oral and/or parenteral routes due to the higher concentration of drug reaching the primary region of infection in the lungs. This study investigated the influence of the amino acid l-leucine alone and in combination with the phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), on the aerosolization behaviour of the anti-TB drugs, pyrazinamide and moxifloxacin HCl. Spray dried powders of pyrazinamide (P), moxifloxacin (M) alone and in combination with 10% l-leucine (PL and ML) and 10% DPPC (PLD and MLD) were produced. The particle sizes of all powders except P were in the inhalable size range ( ® , using a Next Generation Impactor revealed fine particle fraction (FPF) values for P, PL and PLD of 18.7 ± 3.4%, 53.0 ± 3.2% and 74.5 ± 5.3% respectively while FPF values for M, ML and MLD were 55.6 ± 3.3%, 74.7 ± 4.7% and 74.1 ± 1.3% respectively. In conclusion, the differences in the aerosolization behaviours of the pyrazinamide and moxifloxacin spray dried powders with and without excipients was a combination of difference in the surface morphology and surface composition.