[Tobramycin aerosol: could the delivery system influence the particle size and deposition in the lower airways?]

Aerosolized tobramycin represents an efficient alternative to the systemic administration, especially in patients with cystic fibrosis and bronchiectasis affected with Pseudomonas aeruginosa infections. Aim of this study was, using a Time Of Flight Aerosol Beam Spectrometer (API Aerosizer Mach2), to compare the granulometric characteristics of tobramycin aerosolized in 1 sec by three nebulizers and, using mathematic models, to value the particles and drug deposition in the lower airways, particularly at: P level, which includes bronchiolar and alveolar tract; TB level, which includes tracheobronchial tract; ET level, which includes the extrathoracic tract; the amount of particles (Dp) and drug (Dd) dispersed.

Nebula Nuovo: Mass Median Aerodynamic Diameter (MMAD): 3,722 microns; Geometric Standard Deviation (GSD): 2,382; Particles deposited-P: 42.86%; TB: 4.99%; ET: 8.7%; Dp: 43.45%; Tobramycin deposited-P: 36.84%; TB: 11.52; ET: 26.36%; Dd: 25.28. Pari IS2: MMAD: 3,179 microns; GSD: 1,367; Particles deposited--P: 41.99%; TB: 8.67%; ET: 17.26%; Dp: 32.07%; Tobramycin deposited-P: 33.19%; TB: 14.37%; ET: 34.12%; Dd: 18.3%. Artsana with Sidestream ampulla-MMAD: 3,083 microns; GSD: 2,313; Particles deposited-P: 43.96%; TB: 7.11%; ET: 6.23%; Dp: 42.68%; Tobramycin deposited-P: 43.63%; TB: 8.1%; ET: 15.3%; Dd: 32.97%.

Differences in nebulizers performance influence therapeutic effects and tobramicyn deposition in the lower airways.