Cascade Impactor Practice for a High Dose Dry Powder Inhaler at 90 L/min: NGI Versus Modified 6-Stage and 8-Stage ACI

Kamiya, Akihiko; Sakagami, Masahiro; Byron, Peter R.

doi:10.1002/jps.21501

Cited by 17 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the wall shear stress equation, the intensity of the wall shear stress depended on the flow velocity, it meant that the preseparator could reduce the trapped particles to reentrain back into the stream flow. Then, it might decrease the percentage wall loss of the impactor, due to the decreased air velocity and smoothed on the wall shear stress [7]. It was found that particle removal depended on the shear stress even when it was not a linear correlation, for which the particle removal phenomena needs to have a critical wall shear stress [23].…”

Section: Wall Shear Stress On the Collection Plate (Impaction Plate)mentioning

confidence: 99%

See 1 more Smart Citation

The Comparison of Fluid Dynamics Parameters in an Andersen Cascade Impactor Equipped With and Without a Preseparator

et al. 2014

View full text Add to dashboard Cite

Abstract. The fluid dynamic data in Andersen cascade impactor (ACI) are still lacking. Airflows and those affected parameters can be predicted in a preseparator and Andersen cascade impactor (ACI) by computational modeling. This study developed a validated computational fluid dynamic (CFD) model of an ACI and investigated the effects of the preseparator on the CFD parameters. Validation of the computational nozzle velocity for each of the stage 0 to stage 5 of the ACI stages was found to be within a 3.56% error. The flow field indicated that the preseparator accelerated the airflow velocity at the induction tube from 1.13 to 3.71±0.09 m/s and 2.40 to 8.68±0.16 m/s (at 28.3 and 60 L/min of flow rate, respectively). The preseparator produced a nozzle's wall shear stress ranged from 0.08 to 0.34 Pa on a collection plate, while the ex-preseparator spread wall shear from the plate's center was in a range of 0.11 to 0.37 Pa (at 28.3 L/min of flow rate). Moreover, the nozzle velocities increased along the distance from the middle of the collection plate to the periphery. The CFD explained the airflow of the preseparator equipped model by accelerating the airflow along the inlet port to maximize the trapping of desirable particles and the generation of a smooth wall shear stress at the collection plate to reduce the particle reentrainment. While, the ex-preseparator generated an airflow that resulted in a higher wall shear stress occurring on the lower stages.

show abstract

Section: Wall Shear Stress On the Collection Plate (Impaction Plate)mentioning

confidence: 99%

“…Conventionally, a dry powder inhaler can be used at an airflow rate of from 28.3 to 90 L/min during an aerodynamic sizing experiment. Several studies have used a preseparator containing liquid or solvent to trap the powder that was overloaded before reaching the cascade impactor stage [6,7].…”

Section: Introductionmentioning

confidence: 99%

The Comparison of Fluid Dynamics Parameters in an Andersen Cascade Impactor Equipped With and Without a Preseparator

et al. 2014

View full text Add to dashboard Cite

show abstract

“…For the test, powders (25 mg) were accurately weighed and loaded into size 3 gelatin capsules, and subsequently placed into a Cyclohaler ® (Pharmachemie BV, Netherlands) DPI device, connected via a mouthpiece adapter to the USP throat. The powders were subsequently aerosolized (35% relative humidity, 20°C) at 60 L/min for 5 seconds [22,23]. Two capsules (equivalent to 100 μg salbutamol sulphate) were used for each test, and each powder was tested in triplicate.…”

Section: In-vitro Powder Aerosolisationmentioning

confidence: 99%

Influence of excipients on spray-dried powders for inhalation

Xu¹,

Guo²,

Xu³

et al. 2014

Powder Technology

View full text Add to dashboard Cite

“…Therefore, the availability of different in vitro methods can impede regulatory evaluation. Some studies compared two or three in vitro methods for aerodynamic assessment of DPIs [23,[26][27][28][29][30][31][32][33], but their results were inconclusive. While some of the studies indicated similarities between ACI and NGI results [26,29,31], there were also reports on diverging results obtained by these two methods [28,29].…”

Section: Introductionmentioning

confidence: 99%

“…Some studies compared two or three in vitro methods for aerodynamic assessment of DPIs [23,[26][27][28][29][30][31][32][33], but their results were inconclusive. While some of the studies indicated similarities between ACI and NGI results [26,29,31], there were also reports on diverging results obtained by these two methods [28,29]. In addition, some differences were shown between NGI and MSLI [28], TSI [33] or FSI results [27].…”

Section: Introductionmentioning

confidence: 99%

Comparative Assessment of In Vitro and In Silico Methods for Aerodynamic Characterization of Powders for Inhalation

et al. 2021

View full text Add to dashboard Cite

In vitro assessment of dry powders for inhalation (DPIs) aerodynamic performance is an inevitable test in DPI development. However, contemporary trends in drug development also implicate the use of in silico methods, e.g., computational fluid dynamics (CFD) coupled with discrete phase modeling (DPM). The aim of this study was to compare the designed CFD-DPM outcomes with the results of three in vitro methods for aerodynamic assessment of solid lipid microparticle DPIs. The model was able to simulate particle-to-wall sticking and estimate fractions of particles that stick or bounce off the inhaler’s wall; however, we observed notable differences between the in silico and in vitro results. The predicted emitted fractions (EFs) were comparable to the in vitro determined EFs, whereas the predicted fine particle fractions (FPFs) were generally lower than the corresponding in vitro values. In addition, CFD-DPM predicted higher mass median aerodynamic diameter (MMAD) in comparison to the in vitro values. The outcomes of different in vitro methods also diverged, implying that these methods are not interchangeable. Overall, our results support the utility of CFD-DPM in the DPI development, but highlight the need for additional improvements in these models to capture all the key processes influencing aerodynamic performance of specific DPIs.

show abstract

Cascade Impactor Practice for a High Dose Dry Powder Inhaler at 90 L/min: NGI Versus Modified 6-Stage and 8-Stage ACI

Cited by 17 publications

References 18 publications

The Comparison of Fluid Dynamics Parameters in an Andersen Cascade Impactor Equipped With and Without a Preseparator

The Comparison of Fluid Dynamics Parameters in an Andersen Cascade Impactor Equipped With and Without a Preseparator

Influence of excipients on spray-dried powders for inhalation

Comparative Assessment of In Vitro and In Silico Methods for Aerodynamic Characterization of Powders for Inhalation

Contact Info

Product

Resources

About