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Comparative Study
. 2025 May 16;26(5):138.
doi: 10.1208/s12249-025-03136-1.

Assessment of Emergency Spacers Versus Traditional Spacers, An In-Vitro Model for Aerosol Delivery

Omar Ahmed Sayed  1 , Mohamed E A Abdelrahim  2 , Nabila Ibrahim Laz  3 , Haitham Saeed  2   4
Affiliations
Comparative Study

Assessment of Emergency Spacers Versus Traditional Spacers, An In-Vitro Model for Aerosol Delivery

Omar Ahmed Sayed et al. AAPS PharmSciTech. .

Abstract

Spacers, when used with pressurized metered dose inhalers (pMDIs), enhance aerosol drug delivery and address coordination challenges during inhalation. This study aimed to compare the efficacy of emergency spacers with traditional spacers in delivering salbutamol aerosol from pMDIs. The total emitted dose (TED) and particle size distribution of salbutamol were determined using an Andersen MKII cascade impactor. The study evaluated pMDI alone and with various spacers, including traditional antistatic spacers (Able, Tips-Haler, Aerochamber Plus Flow Vu, Atomizer Chamber) and emergency spacers (Plastic juice cup, MDI PLUS, Lite-Air spacer, DispozABLE spacer, and Paper sheet spacer) at a flow rate of 28.3 L/min with inhalation volumes of 2 L and 4 L, representing children (> 6 years) and adults, respectively. The pMDI alone delivered the highest TED, significantly exceeding all pMDI-spacer combinations at both inhalation volumes (P < 0.001-0.033), except for the Aerochamber Plus Flow Vu at 2 L. The Aerochamber Plus Flow Vu achieved significantly higher TED compared to emergency spacers and the Atomizer Chamber (P < 0.001-0.039) and was non-significantly higher than the Able and Tips-Haler spacers. It also delivered the highest fine particle dose (≤ 5 µg) and exhibited the lowest mass median aerodynamic diameter (MMAD) with significant differences across devices. Traditional spacers, particularly the Aerochamber Plus Flow Vu, demonstrated superior performance in TED and aerodynamic particle size distribution. However, emergency spacers remain viable alternatives in urgent situations due to their acceptable delivery efficiency.

Keywords: PMDI; aerosol delivery; emergency spacers; salbutamol; valved holding chambers.

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Conflict of interest statement

Declarations. Conflict of interest: None.

References

    1. Borghardt JM, Kloft C, Sharma A. Inhaled therapy in respiratory disease: the complex interplay of pulmonary kinetic processes. Can Respir J. 2018;2018(1):2732017. - PubMed - PMC
    1. Nicola M, Soliman YM, Hussein R, Saeed H, Abdelrahim M. Comparison between traditional and nontraditional add-on devices used with pressurised metered-dose inhalers. ERJ Open Res. 2020;6(4):00073–2020. - PubMed - PMC - DOI
    1. Salvi S, Shevade M, Aggarwal A, Apte K, Barne M, Mohan M, et al. A practical guide on the use of inhaler devices for asthma and COPD. J Assoc Physicians India. 2021;69:8–26.
    1. Shakshuki A, Agu RU. Improving the efficiency of respiratory drug delivery: a review of current treatment trends and future strategies for asthma and chronic obstructive pulmonary disease. Pulmonary Therapy. 2017;3(2):267–81. - PubMed - PMC - DOI
    1. Saeed H, Abdelrahim ME, Rabea H, Salem HF. Evaluation of disposable and traditional accessory devices for use with a pressurized metered-dose inhaler. Respir Care. 2020;65(3):320–5. - PubMed - DOI

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