Effect of Drug Targeting Nebulization on Lung Deposition: A Randomized Crossover Scintigraphic Comparison Between Central and Peripheral Delivery

Abstract

BACKGROUND: Recent technological advances in nebulization permit researchers to target specific parts of the lungs by modifying delivery method. The aim of this study was to compare the central and peripheral targeted modalities of administration. METHODS: Lung and regional deposition of inhaled technetium-99m diethylene triamine penta-acetic was measured by scintigraphy after peripheral and central targeted modalities of administration with an Akita device in 6 healthy subjects. RESULTS: Drug targeting nebulization delivered a large amount of drug into the peripheral part of the lung independent of the modality (outer-to-inner deposition ratio of 1.24 ؎ 0.21 vs 1.22 ؎ 0.14 for central and peripheral modalities, respectively), but there was no difference in lung deposition (whole-body deposition, 83.3 ؎ 6.5% vs 82.8 ؎ 7.3%, P ‫؍‬ .86) or regional deposition (P ‫؍‬ .77) between both modalities. The extrathoracic deposition was < 20% of the wholebody deposition, without a difference between modalities (P ‫؍‬ .86). CONCLUSIONS: This study shows for the first time that choosing 2 different specific drug targeting nebulization modes does not influence the amount of drug delivered into the lung in healthy male subjects. Moreover, the modes do not modify the site of deposition under the conditions of our study.

Targeted Lung Deposition From Nebulization Is Not Improved in the Lateral Decubitus Position in Healthy Volunteers

“…Our results also confirm the low variability in deposition when nebulizing with a controlleddose inhalation drug-delivery system (ie, AKITA Jet). 20,21 A difference in total lung deposition related to body position was previously suggested and explained by an increased extrathoracic deposition, but this observation was only based on the results for one subject. 22 No difference in tracheal and extrathoracic deposition was observed in our study, although extrathoracic deposition probably contributed to the reduced total lungs deposition in the left lateral decubitus position.…”

“…To detect a minimal difference of 10% of total lung deposition during nebulization between the 2 sessions, accepting an alpha risk of 0.05 and a beta risk of 0.2 in a 2-sided test, and assuming that 6% is the standard deviation of the difference in the response to treatment for the same participant, 20 6 subjects were necessary.…”

Pulmonary Drug Delivery Following Continuous Vibrating Mesh Nebulization and Inspiratory Synchronized Vibrating Mesh Nebulization During Noninvasive Ventilation in Healthy Volunteers

“…The time for the nebulized drug to reach the lungs before the onset of exhalation could have been too short, especially in subjects with low Ti/Ttot. (12,21,42) Therefore, a higher amount of drug might have been delivered to the oropharynx (43) and lost in the circuit (including the face mask), (21) thereby reducing the deep pulmonary delivery (e.g., alveolar spaces) with Inspi-Neb. (12,21,42,44) (3) The delay of 20 milliseconds measured between the end of insufflation and the stop actuation of the nebulizer (unpublished data) could have increased the amount of drug lost during exhalation.…”

Inhalation Techniques Used in Patients with Respiratory Failure Treated with Noninvasive Mechanical Ventilation

“…Comparatively, a study on healthy individuals was conducted to measure central and peripheral pulmonary deposition of radiolabeled diethylenetriaminepentaacetic acid (DTPA). The lung deposition was measured to be >80%, whereas extrathoracic deposition was below 20% of the body deposition [ 62 ]. Aerosol therapy during NIV has become a common practice, especially in patients with acute onset of respiratory symptoms, due to clinical benefits and such treatment's effectiveness [ 63 ].…”