The importance of interaction between particles for the application of powder for inhalation

用于治疗支气管哮喘的药剂颗粒必须具有在1微米和5微米之间的尺寸，所述药剂颗粒可以通过吸入到达肺的细肺泡。然而，这种颗粒非常粘聚、流动性差且难以分散。因此，它们在混合器中与变得包覆的较粗颗粒共混。在吸入过程中，药剂颗粒必须再次与载体分离。因此，载体和药剂之间的粘附力在生产和处理过程中必须足够强，但另一方面又足够小以在吸入器装置中再次与载体分离。因此，控制粘附力是非常重要的。第一个项目期的目标是通过玻璃珠载体的表面处理有针对性地改变粘附力。此外，第一和第二个项目期间的目标是在格子玻尔兹曼方法的基础上，使用不同表面处理的粘附力的实验信息，对分离概率进行数值流模拟。第二个项目期的主要目标是考虑不同制剂颗粒的大小、形状和化学性质，以提供数据库。这应允许根据试剂颗粒的性质适当选择载体颗粒。拟议项目的主要目标是优化吸入器的几何形状，以提高其效率（即到达肺部的制剂颗粒量）。这应在实验研究的基础上进行，使用模块化设施，并对整个吸入器进行数值流量计算，并结合开发的分离模型。因此，可以有针对性地调节影响药剂脱离的粉末吸入影响因素的所有性质。因此，迄今为止基于试错程序的粉末吸入剂的开发将被更科学的方法所取代。

Agent particles for the therapy of bronchial asthma which can reach the fine alveoli of the lung through inhalation must have sizes between 1 micron and 5 micron. Such particle however are very cohesive, a poor flowability and are difficult to disperse. Consequently they are blended in a mixer with coarser particles which become coated. During the inhalation process the agent particles must be detached again from the carrier. Hence, the adhesion force between carrier and agent must be strong enough during the production and handling process, but on the other hand small enough to be detached from the carrier again in the inhaler device. For this reason the control of the adhesion force is very important. The objective of the first project period was the targeted modification of the adhesion force through surface treatment of the glass bead carrier. Furthermore, an objective of the first and second project period was the numerical flow simulation of the detachment probability on the basis of the Lattice-Boltzmann method using experimental information on the adhesion forces for different surface treatment. The main objective of the second project period was the consideration of size, shape and chemistry of different agent particles for providing a data base. This should allow a proper selection of the carrier particle, depending on the agent particle properties. The main goal of the proposed project is the optimization of the inhaler geometry in order to improve its efficiency (i.e. amount of agent particles reaching the lung). This shall be done on the basis of experimental studies using a modular facility and applying numerical flow calculations of the entire inhaler incorporating a developed detachment model. Thereby, all the properties of the powder inhalation influencing factors, which influence the agent detachment, can be targeted adjusted. With that, the development of powder inhalants so far based on try and error procedures will be replaced by a more scientific approach.