Purpose

In order to improve the delivery of dry powder aerosol formulations to the lungs of infants, this study implemented an infant air-jet platform and explored the effects of different air sources, flow rates, and pulmonary mechanics on aerosolization performance and aerosol delivery through a preterm nose-throat (NT) in vitro model.

Methods

The infant air-jet platform was actuated with a positive-pressure air source that delivered the aerosol and provided a full inhalation breath. Three different air sources were developed to provide highly controllable positive-pressure air actuations (using actuation volumes of ~10 mL for the preterm model). While providing different flow waveform shapes, the three air sources were calibrated to produce the same flow rate magnitude (Q90: 90th percentile of flow rate). Multiple air-jet DPI designs were coupled with the air sources and evaluated with a model spray-dried excipient enhanced growth formulation.

Results

Compared to other designs, the D1-Single air-jet DPI provided improved performance with low variability across all three air sources. With the tested D1-Single air-jet and Timer air source, reducing the flow rate from 4 to 1.7 L/min marginally decreased the aerosol size and significantly increased the lung delivery efficiency above 50% of the loaded dose. These results were not impacted by the presence of downstream pulmonary mechanics (resistance and compliance model).

Conclusions

The selected design was capable of providing an estimated >50% lung delivery efficiency of a model spray-dried formulation and was not influenced by the air source, thereby enabling greater flexibility for platform deployment in different environments.

中文翻译：

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婴儿喷气干粉吸入器 (DPI) 的进步：不同正压气源和流速的评估

目的

为了改善干粉气雾剂制剂向婴儿肺部的输送，本研究实施了一个婴儿喷气平台，探讨了不同气源、流速和肺力学对早产儿雾化性能和气雾剂输送的影响。鼻喉（NT）体外模型。

方法

婴儿喷气式平台由一个正压气源驱动，该气源输送气溶胶并提供完整的吸入呼吸。开发了三种不同的空气源以提供高度可控的正压空气驱动（使用约 10 mL 的驱动体积用于早产模型）。在提供不同的流量波形形状的同时，对三个空气源进行校准以产生相同的流量幅度（Q90：流量的第 90 个百分位数）。多种空气喷射 DPI 设计与空气源相结合，并使用模型喷雾干燥赋形剂增强生长配方进行评估。

结果

与其他设计相比，D1-Single 喷气式 DPI 提供了改进的性能，并且所有三个空气源的可变性都较低。使用测试的 D1-Single 空气喷射和 Timer 空气源，将流速从 4 降低到 1.7 L/min 略微降低了气溶胶尺寸，并显着提高了 50% 以上加载剂量的肺输送效率。这些结果不受下游肺力学（阻力和顺应性模型）的影响。

结论

所选设计能够提供模型喷雾干燥配方的估计 > 50% 的肺输送效率，并且不受空气源的影响，从而为不同环境中的平台部署提供更大的灵活性。