Related Experiment Video
Updated: Mar 10, 2026

Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System
Published on: April 6, 2017
Drug Delivery in Asthmatic Children Following Coordinated and Uncoordinated Inhalation Maneuvers: A Randomized
Ariel Berlinski1, Dirk von Hollen2, Ross H M Hatley3
11 Pulmonology Section, Department of Pediatrics, UAMS/COM , Pediatric Aerosol Research Laboratory, Little Rock, Arkansas.
Background:
Valved holding chambers (VHCs) are used in children to deliver pressurized metered dose inhalers (pMDI). In vitro data suggest that uncoordinated use decreases the amount of drug available for inhalation. We hypothesize that in an ex vivo study, the coordinated maneuver will deliver more drug than the uncoordinated one.
Patients And Methods:
Thirty-two clinically stable asthmatic children, ages 5-8 years, completed the study. An aerosol filter was interposed between a small-volume nonelectrostatic VHC and a mouthpiece to capture the drug emitted by one puff of Flovent® 220 mcg during tidal breathing. Inhalation and actuation parameters were measured by an electronic monitor, and the number of breaths required to empty the VHC was calculated. Subjects completed three coordinated and three uncoordinated (actuation at the beginning of inhalation and exhalation, respectively) runs in random order. Drug content from the filter and VHC was measured by high-performance liquid chromatography and expressed as percentage of emitted dose.
Results:
[mean (99% confidence interval)] Filter dose was higher during coordinated technique 46% (43%-50%) than during uncoordinated technique 41% (37%-44%) (p < 0.001). Peak inspiratory flow and tidal volume were 23.2 L/min (21.3-25.1 L/min) and 281 mL (251-311 mL), respectively. Subjects required three breaths to empty the VHC in 96% of the tests.
Conclusions:
Actuating the pMDI into a small-volume nonelectrostatic VHC during exhalation reduced by 11% the amount of fluticasone captured at the exit of the VHC. Asthmatic children (5-8 years old) need three or less breaths to empty the small-volume VHC (NCT01714063).
Related Concept Videos
Inhaled Medications
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce...
Drugs Used in Lower Respiratory Disorders: Overview
Bronchodilators, the first step of respiration enhancement, come in various forms, each with its own mechanism...
Drug Delivery: Miscellaneous Routes
Oral inhalation and nasal sprays swiftly transfer drugs across the respiratory epithelium's mucosal layer. Inhaled glucocorticoids and bronchodilators directly target lung conditions such as asthma, while fluticasone nasal spray mitigates allergic rhinitis.
Transdermal patches transport drugs...
Additional Routes of Drug Administration
Administering drugs via inhalation allows for the direct delivery of gaseous, volatile substances or droplets to different parts of the respiratory tract. One of the advantages of the inhalation route is the rapid absorption of drugs into the circulatory system, which is possible because of the large surface area of...

