Next Article in Journal
Penetration Enhancers in Ocular Drug Delivery
Next Article in Special Issue
Comparison of Oral, Intranasal and Aerosol Administration of Amiodarone in Rats as a Model of Pulmonary Phospholipidosis
Previous Article in Journal
Intracellular Signaling in Key Pathways Is Induced by Treatment with Ultrasound and Microbubbles in a Leukemia Cell Line, but Not in Healthy Peripheral Blood Mononuclear Cells
Previous Article in Special Issue
Epoprostenol Delivered via High Flow Nasal Cannula for ICU Subjects with Severe Hypoxemia Comorbid with Pulmonary Hypertension or Right Heart Dysfunction
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessArticle

Impact of Gas Flow and Humidity on Trans-Nasal Aerosol Deposition via Nasal Cannula in Adults: A Randomized Cross-Over Study

Department of Physical Therapy, Universidade Federal de Pernambuco, Recife 50740-560, PE, Brazil
Department of Respiratory Therapy, Texas State University, Round Rock, TX 78665, USA
Medicine Nuclear Department, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
Aerogen Pharma Corp, San Mateo, CA 94402, USA
Avenida Jornalista Aníbal Fernandes, SN—Cidade Universitária, CEP, Recife 50740-560, PE, Brazil
Author to whom correspondence should be addressed.
Pharmaceutics 2019, 11(7), 320;
Received: 27 May 2019 / Revised: 4 July 2019 / Accepted: 4 July 2019 / Published: 7 July 2019
(This article belongs to the Special Issue Advances in Pulmonary Drug Delivery)
PDF [1812 KB, uploaded 7 July 2019]


Background: Trans-nasal pulmonary aerosol delivery using high flow nasal cannula (HFNC) devices is described with the administration of high gas flows exceeding patient inspiratory flow (HF) and with lower flows (LF). The aim of this pilot clinical trial was to compare deposition and distribution of radiolabeled aerosol via nasal cannula in healthy adults across three rates of gas flow delivered with active heated humidification, and to further identify the impact of aerosol administration without heated humidity. Methods: Twenty-three (23) healthy adults (16F) were randomized to receive aerosol with active heated humidification or unheated oxygen at gas flows of 10 L/min (n = 8), 30 L/min (n = 7), or 50 L/min (n = 8). Diethylenetriaminepentaacetic acid labeled with 1 millicurie (37 MBq) of Technetium-99m (DTPA-Tc99m) was mixed with NaCl to a fill volume of 1 mL, and administered via mesh nebulizer placed at the inlet of the humidifier. Radioactivity counts were performed using a gamma camera and the regions of interest (ROIs) were delimited with counts from the lungs, upper airways, stomach, nebulizer, circuit, and expiratory filter. A mass balance was calculated and each compartment was expressed as a percentage of the total. Results: Lung deposition (mean ± SD) with heated humidified gas was greater at 10 L/min than 30 L/min or 50 L/min (17.2 ± 6.8%, 5.71 ± 2.04%, and 3.46 ± 1.24%, respectively; p = 0.0001). Using unheated carrier gas, a lung dose of aerosol was similar to the active heated humidification condition at 10 L/min, but greater at 30 and 50 L/min (p = 0.011). Administered gas flow and lung deposition were negatively correlated (r = −0.880, p < 0.001). Conclusions: Both flow and active heated humidity inversely impact aerosol delivery through HFNC. Nevertheless, aerosol administration across the range of commonly used flows can provide measurable levels of lung deposition in healthy adult subjects (NCT 02519465). View Full-Text
Keywords: nasal cannula; humidity; aerosol; scintigraphy; oxygen and nebulizer nasal cannula; humidity; aerosol; scintigraphy; oxygen and nebulizer

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Alcoforado, L.; Ari, A.; Barcelar, J.M.; Brandão, S.C.S.; Fink, J.B.; de Andrade, A.D. Impact of Gas Flow and Humidity on Trans-Nasal Aerosol Deposition via Nasal Cannula in Adults: A Randomized Cross-Over Study. Pharmaceutics 2019, 11, 320.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Pharmaceutics EISSN 1999-4923 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top