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Three-dimensional DEM-CFD analysis of air-flow-induced detachment of API particles from carrier particles in dry powder inhalers.

Yang J, Wu CY, Adams M - Acta Pharm Sin B (2014)

Bottom Line: A carrier-based agglomerate is initially formed and then dispersed in a uniformed air flow.It is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be dispersed.It is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance, which is governed by the ratio of the fluid drag force to the pull-off force.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK ; Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK.

ABSTRACT
Air flow and particle-particle/wall impacts are considered as two primary dispersion mechanisms for dry powder inhalers (DPIs). Hence, an understanding of these mechanisms is critical for the development of DPIs. In this study, a coupled DEM-CFD (discrete element method-computational fluid dynamics) is employed to investigate the influence of air flow on the dispersion performance of the carrier-based DPI formulations. A carrier-based agglomerate is initially formed and then dispersed in a uniformed air flow. It is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be dispersed. Furthermore, the influence of the air velocity and work of adhesion are also examined. It is shown that the dispersion number (i.e., the number of API particles detached from the carrier) increases with increasing air velocity, and decreases with increasing the work of adhesion, indicating that the DPI performance is controlled by the balance of the removal and adhesive forces. It is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance, which is governed by the ratio of the fluid drag force to the pull-off force.

No MeSH data available.


Related in: MedlinePlus

The detachment process at various time instants. (a) t=4.55×10−5 s; (b) t=9.09×10−5 s; (c) t=1.36×10−4 s; (d) t=2.05×10−4 s.
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f0010: The detachment process at various time instants. (a) t=4.55×10−5 s; (b) t=9.09×10−5 s; (c) t=1.36×10−4 s; (d) t=2.05×10−4 s.

Mentions: Fig. 2 shows a typical detachment process at different time instants. In Fig. 1b, API particles are randomly attached to the carrier surface before air flow is introduced. When the air flow is introduced, the API particles in the downstream regions are removed directly (Fig. 2a). Meanwhile, the API particles in the middle regions move (either slide or roll) around the carrier to the downstream regions and then detach from the carrier (Fig. 2b and c). Thereafter, most API particles are detached from the carrier while the API particles in the upstream regions are not removed and still in contact with the carrier (Fig. 2d).


Three-dimensional DEM-CFD analysis of air-flow-induced detachment of API particles from carrier particles in dry powder inhalers.

Yang J, Wu CY, Adams M - Acta Pharm Sin B (2014)

The detachment process at various time instants. (a) t=4.55×10−5 s; (b) t=9.09×10−5 s; (c) t=1.36×10−4 s; (d) t=2.05×10−4 s.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590728&req=5

f0010: The detachment process at various time instants. (a) t=4.55×10−5 s; (b) t=9.09×10−5 s; (c) t=1.36×10−4 s; (d) t=2.05×10−4 s.
Mentions: Fig. 2 shows a typical detachment process at different time instants. In Fig. 1b, API particles are randomly attached to the carrier surface before air flow is introduced. When the air flow is introduced, the API particles in the downstream regions are removed directly (Fig. 2a). Meanwhile, the API particles in the middle regions move (either slide or roll) around the carrier to the downstream regions and then detach from the carrier (Fig. 2b and c). Thereafter, most API particles are detached from the carrier while the API particles in the upstream regions are not removed and still in contact with the carrier (Fig. 2d).

Bottom Line: A carrier-based agglomerate is initially formed and then dispersed in a uniformed air flow.It is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be dispersed.It is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance, which is governed by the ratio of the fluid drag force to the pull-off force.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK ; Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK.

ABSTRACT
Air flow and particle-particle/wall impacts are considered as two primary dispersion mechanisms for dry powder inhalers (DPIs). Hence, an understanding of these mechanisms is critical for the development of DPIs. In this study, a coupled DEM-CFD (discrete element method-computational fluid dynamics) is employed to investigate the influence of air flow on the dispersion performance of the carrier-based DPI formulations. A carrier-based agglomerate is initially formed and then dispersed in a uniformed air flow. It is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be dispersed. Furthermore, the influence of the air velocity and work of adhesion are also examined. It is shown that the dispersion number (i.e., the number of API particles detached from the carrier) increases with increasing air velocity, and decreases with increasing the work of adhesion, indicating that the DPI performance is controlled by the balance of the removal and adhesive forces. It is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance, which is governed by the ratio of the fluid drag force to the pull-off force.

No MeSH data available.


Related in: MedlinePlus