Towards the optimisation and adaptation of dry powder inhalers
Towards the optimisation and adaptation of dry powder inhalers
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DOI：
10.1016/j.ijpharm.2014.04.065
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发表时间：
2014-08-15
影响因子：
5.8
通讯作者：
Urbanetz, N.
中科院分区：
文献类型：
--
作者：
Cui, Y.;Schmalfuss, S.;Urbanetz, N.
通过干粉吸入器的肺部药物递送变得越来越受欢迎。这种吸入装置必须确保在吸入过程中，由于流体流动应力，药物粉末与载体分离。该项目的目标是开发一种药物粉末分离模型，用于通过吸入器的流体流动和载体颗粒运动的数值计算（CFD，计算流体动力学）以及由此产生的药物输送效率。该方案将成为优化吸入器几何形状和干粉吸入器配方的基础。为此，采用了多尺度方法。首先，用OpenFOAM（R）数值计算通过吸入器的流场，并记录载体颗粒所经历的流动应力。该信息用于使用格子玻尔兹曼方法的微尺度模拟，其中仅一个覆盖有药物粉末的载体颗粒被放置在立方流域中并暴露于相关的流动情况，例如具有不同雷诺数的塞流和剪切流。由此获得药物颗粒上的流体力。为了允许通过剥离、滑动或滚动确定药物颗粒脱离的可能性，还通过AFM（原子力显微镜）对不同的载体颗粒表面结构进行测量。接触性能，如货车范德华力，摩擦系数和粘附表面能被用来确定，从力或力矩平衡（流体力与接触力），作为载体颗粒雷诺数的函数的三种机制的分离概率。这些结果将用于推导药物粉末分离模型。(C)2014爱思唯尔有限公司版权所有。
Pulmonary drug delivery by dry powder inhalers is becoming more and more popular. Such an inhalation device must insure that during the inhalation process the drug powder is detached from the carrier due to fluid flow stresses. The goal of the project is the development of a drug powder detachment model to be used in numerical computations (CFD, computational fluid dynamics) of fluid flow and carrier particle motion through the inhaler and the resulting efficiency of drug delivery. This programme will be the basis for the optimisation of inhaler geometry and dry powder inhaler formulation. For this purpose a multi-scale approach is adopted. First the flow field through the inhaler is numerically calculated with OpenFOAM (R) and the flow stresses experienced by the carrier particles are recorded. This information is used for micro-scale simulations using the Lattice Boltzmann method where only one carrier particle covered with drug powder is placed in cubic flow domain and exposed to the relevant flow situations, e.g. plug and shear flow with different Reynolds numbers. Therefrom the fluid forces on the drug particles are obtained. In order to allow the determination of the drug particle detachment possibility by lift-off, sliding or rolling, also measurements by AFM (atomic force microscope) were conducted for different carrier particle surface structures. The contact properties, such as van der Waals force, friction coefficient and adhesion surface energy were used to determine, from a force or moment balance (fluid forces versus contact forces), the detachment probability by the three mechanisms as a function of carrier particle Reynolds number. These results will be used for deriving the drug powder detachment model. (C) 2014 Elsevier B.V. All rights reserved.