Rapid pulmonary delivery of inhaled tobramycin for Pseudomonas infection in cystic fibrosis: a pilot project

Pediatr Pulmonol. 2008 Aug;43(8):753-9. doi: 10.1002/ppul.20850.


Background: Patients with cystic fibrosis spend as much 30 min a day inhaling tobramycin. Could a new rapid system deposit the equivalent amount of tobramycin faster?

Methods: Six healthy adult males inhaled 5 ml (300 mg) of tobramycin from a breath enhanced nebulizer and either 125 mg (n = 3) or 150 mg (n = 3) from a vibrating membrane system with a large or small aerosol mixing chamber respectively. A radiolabel was added to the solution and shown to "track" with the tobramycin. Imaging was done with a dual headed gamma camera. Because the radiolabel will be cleared by mucociliary action during administration, algorithms were developed to allow the comparison of a slower system to a faster one.

Results: Both formulations were well tolerated. The lung deposition was 16.6 +/- 3.2% (mean +/- SD) of the charge dose delivered in 10.9 +/- 1.0 min for the breath enhanced nebulizer versus 32.0 +/- 5.1% delivered in 2.5 +/- 0.4 min from the vibrating membrane system. The absolute pulmonary delivery of tobramycin was 49.9 +/- 9.6 versus 43.9 +/- 4.8 mg for the two systems respectively, differences that were statistically significant (pair t-test) but unlikely to be clinically significant. There was a similar deposition of tobramycin for the 125 and 150 mg dose.

Conclusions: It is possible to deliver an equivalent amount of tobramycin in a shorter period of time with the new vibrating membrane system and a more concentrated formulation. These data will allow the design of a comparison in patients with CF.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Adult
  • Anti-Bacterial Agents / administration & dosage*
  • Anti-Bacterial Agents / pharmacokinetics
  • Cystic Fibrosis / drug therapy*
  • Cystic Fibrosis / microbiology*
  • Humans
  • Male
  • Middle Aged
  • Nebulizers and Vaporizers
  • Pilot Projects
  • Pseudomonas Infections / drug therapy*
  • Time Factors
  • Tobramycin / administration & dosage*
  • Tobramycin / pharmacokinetics
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Tobramycin