Evidence map›Paper›PMID 42413639›Full record

ArticleInternational journal of pharmaceutics2026

In situ characterization of aerosol deposition in dry powder inhalers using optical coherence tomography.

Taye Tolu Mekonnen, Liam Milton-McGurk, Waiting Tai, Patricia Tang, Shaokoon Cheng, Hak-Kim Chan, Susan Boc, Ross Walenga, Elizabeth Bielski, Bryan Newman and 1 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in International journal of pharmaceutics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Taye Tolu MekonnenSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
Liam Milton-McGurkSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia; School of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
Waiting TaiSydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia.
Patricia TangSydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia.
Shaokoon ChengSchool of Engineering, Macquarie University, Sydney, NSW 2109, Australia.
Hak-Kim ChanSydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia.
Susan BocDivision of Therapeutic Performance I, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Ross WalengaDivision of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Elizabeth BielskiDivision of Therapeutic Performance I, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Bryan NewmanDivision of Therapeutic Performance I, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Agisilaos KourmatzisSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia. Electronic address: agisilaos.kourmatzis@sydney.edu.au.

Funding

Intramural FDA HHS FD999999
6 · The paper itself

Abstract

This study employs high-resolution Optical Coherence Tomography (OCT) to characterize aerosol deposition within a model Dry Powder Inhaler (DPI). Deposition was examined for five in-house formulations containing different mass fractions of coarse lactose carrier (SV010), fine lactose (LH300), and Salbutamol Sulphate (SS), and for two commercial formulations, namely Aridol® (mannitol) and Pulmicort Flexhaler™ (budesonide). Experiments were performed at dispersion flow rates of 30 LPM and 50 LPM to evaluate the influence of formulation composition and aerodynamic conditions. Three-dimensional OCT mapping revealed that the in-house formulations, comprising over 90% (w/w) coarse excipients, deposited predominantly as discrete clusters of particles distributed across the DPI surface. Increasing flow rate led to reduced average cluster size while increasing cluster density. Deposition thickness increased with SS content, from 94 ± 24 µm for SV010 (0% SS) to 205 ± 18 µm for formulation F12 (4.5% SS), while the addition of fine lactose produced thicker depositions than the coarse carrier alone but thinner than formulations with the same fraction of SS without fines. Thickness distribution analysis demonstrated broad, formulation- and flow-dependent profiles with distinct modal values, providing a more comprehensive understanding of deposition behaviour than mean or peak measures. Both in-house and commercial formulations exhibited strong peripheral loading, with more than 70% of total deposited volume confined within the first 10% of radial distance from the swirl-chamber edge. Overall, the results demonstrate the potential of OCT as a diagnostic tool for quantifying spatially resolved deposition relevant to DPI design and formulation-device optimization.

Indexed as

Dry Powder InhalersTomography, Optical CoherenceAdministration, InhalationAerosolized Particles and DropletsAerosolsAlbuterolBudesonideChemistry, PharmaceuticalExcipientsLactoseMannitolParticle SizeAerosolized Particles and DropletsAerosolsAlbuterolBudesonideExcipientsLactoseMannitolDeposition imagingDeposition thicknessDry powder inhaler (DPI)Optical coherence tomography (OCT)Thickness distribution

Identifiers

PMID42413639
PMCPMC13510191

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.