Background: The I-neb AAD System was designed to deliver aerosol with two different breathing pattern algorithms: the Tidal Breathing Mode (TBM) and the Target Inhalation Mode (TIM). For the purpose of the study, the TBM breathing pattern algorithm was set to guide the subjects to inhalation during tidal breathing with aerosol pulsed during 50-80% of the time spent on inhalation, whereas the TIM breathing pattern was set to guide the subject to a slow and deep inhalation of up to approximately 9 sec with aerosol pulsed for up to 7 sec, leaving 2 sec for particle deposition in the lungs. In TIM, the inspiratory flow was guided to approximately 20 L/min through a built-in resistance in the mouthpiece.
Methods: We have, in a randomized, open-label, crossover study of 12 healthy subjects evaluated lung deposition following administration of a radiolabeled aerosol from the I-neb AAD System with the TBM and TIM breathing patterns.
Results: The results showed that mean lung deposition was significantly higher when using the I-neb AAD System with the TIM breathing pattern (73.3%) than with the TBM breathing pattern (62.8%). The mean exhaled fractions were low (<1%) for both breathing patterns. The nebulization time was significantly shorter with the TIM breathing pattern (3.0 min) than with the TBM breathing pattern (4.7 min).
Conclusions: The results of the present study showed that lung deposition with the slow and deep inhalation achieved through the I-neb AAD System in TIM was superior to the lung deposition achieved during tidal breathing in TBM. With the combination of high lung deposition, almost no loss of aerosol during exhalation, and short nebulization time the I-neb AAD System with the TIM breathing pattern should be of special value to patients who require multiple daily dosing of aerosolized medication, are using drugs that should not be wasted into the room air, or would benefit from a more efficient delivery system.