Evaluation of the Respimat Soft Mist Inhaler using a Concurrent CFD and In Vitro Approach
Evaluation of the Respimat Soft Mist Inhaler using a Concurrent CFD and In Vitro Approach
复制标题
DOI：
10.1089/jamp.2008.0708
复制
发表时间：
2009-06-01
影响因子：
3.4
通讯作者：
Hindle, Michael
中科院分区：
文献类型：
--
作者：
Longest, P. Worth;Hindle, Michael
背景：据报告，能倍乐软雾吸入器产生的气雾剂具有低喷雾动量和小液滴尺寸。然而，对能倍乐气雾剂的转运特性尚未充分了解。本研究的目的是结合计算流体动力学（CFD）建模和体外实验，表征能倍乐吸入器释放的气雾剂的转运和沉积。方法：评估能倍乐气雾剂在吸入器吸嘴（MP）、标准吸入口（IP）以及在30 L/min的吸入流速下更真实的口-喉（MT）几何形状。（0.6%）溶液，并使用体外实验和能倍乐吸入器的CFD模型定量药物沉积。激光衍射实验被用来确定初始多分散气溶胶粒径distribution.Results和结论：它被发现，气溶胶产生的高度复杂的过程中的射流碰撞和破碎，可以近似的模型，使用有效的喷雾条件。计算预测的沉积分数同意以及在体外结果的IP（误差在20%以内）和MT（误差在10%以内）的几何形状。实验结果表明，药物在MP中的沉积分数为27 - 29%，占总药物损失的大部分。基于计算流体力学的解决方案，高MP沉积是由于围绕气溶胶喷雾并夹带大量小液滴的再循环流型。相比之下，IP（4.2%）和MT（7.4%）几何结构中能倍乐气雾剂的沉积相对较低。本研究的结果表明，对当前能倍乐MP的修改和对特定患者变量的控制可显著减少装置中的沉积，并可减少体内观察到的口咽部药物高损失。
Background: The Respimat Soft Mist Inhaler is reported to generate an aerosol with low spray momentum and a small droplet size. However, the transport characteristics of the Respimat aerosol are not well understood. The objective of this study was to characterize the transport and deposition of an aerosol emitted from the Respimat inhaler using a combination of computational fluid dynamics (CFD) modeling and in vitro experiments.Methods: Deposition of the Respimat aerosol was assessed in the inhaler mouthpiece (MP), a standard induction port (IP), and a more realistic mouth-throat (MT) geometry at an inhalation flow rate of 30 L/min. Aerosols were generated using an albuterol sulfate (0.6%) solution, and the drug deposition was quantified using both in vitro experiments and a CFD model of the Respimat inhaler. Laser diffraction experiments were used to determine the initial polydisperse aerosol size distribution.Results and Conclusions: It was found that the aerosol generated from the highly complex process of jet collision and breakup could be approximated in the model using effective spray conditions. Computational predictions of deposition fractions agreed well with in vitro results for both the IP (within 20% error) and MT (within 10% error) geometries. The experimental results indicated that the deposition fraction of drug in the MP ranged from 27 to 29% and accounted for a majority of total drug loss. Based on the CFD solution, high MP deposition was due to a recirculating flow pattern that surrounded the aerosol spray and entrained a significant number of small droplets. In contrast, deposition of the Respimat aerosol in both the IP (4.2%) and MT (7.4%) geometries was relatively low. Results of this study indicate that modifications to the current Respimat MP and control of specific patient variables may significantly reduce deposition in the device and may decrease high oropharyngeal drug loss observed in vivo.