Recently, statistical techniques such as design of experiments are being applied for efficient optimization of oral formulations. To use these statistical techniques for inhalation formulations, efficient methods for rapid determination of the aerodynamic particle size distribution of many samples are needed. Therefore, we aimed to develop a simple method to measure aerodynamic particle size distribution that closely agrees with the results of inhalation characteristic tests. We added attachments for dispersion to the aerodynamic particle sizer (APS) so that formulations could be dispersed under the same condition as for multi-stage liquid impinger (MSLI) measurement. Then, we examined the correlation between MSLI and APS using lyophilizate for dry powder inhalation formulations that generate porous particles just on inhalation. It is difficult to obtain the accurate aerodynamic particle size distribution of porous particles by APS because the particle density is difficult to estimate accurately. However, there was a significant correlation between MSLI and APS when the particle density settings for APS measurement was calculated by a conversion factor based on the result of MSLI. The APS with dispersion attachments and this conversion factor can measure a number of samples in a short time, thereby enabling more efficient optimization of dry powder inhalers.

中文翻译：

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测量冻干粉吸入干粉时产生的多孔颗粒的空气动力学尺寸分布的简单方法

最近，诸如实验设计之类的统计技术被用于有效优化口服制剂。为了将这些统计技术用于吸入制剂，需要快速确定许多样品的空气动力学粒径分布的有效方法。因此，我们旨在开发一种测量空气动力学粒径分布的简单方法，该方法与吸入特性测试的结果非常吻合。我们在空气动力学粒度仪（APS）中添加了分散附件，以便可以在与多级液体冲击器（MSLI）测量相同的条件下分散制剂。然后，我们使用冻干剂检查了干粉吸入制剂中MSLI和APS之间的相关性，干粉吸入制剂仅在吸入时产生多孔颗粒。通过APS难以获得多孔颗粒的准确的空气动力学粒径分布，因为颗粒密度难以精确估计。但是，当通过基于MSLI结果的转换因子计算APS测量的颗粒密度设置时，MSLI与APS之间存在显着相关性。具有分散附件和此转换因子的APS可以在短时间内测量大量样品，从而可以更有效地优化干粉吸入器。通过基于MSLI结果的转换因子计算用于APS测量的颗粒密度设置时，MSLI与APS之间存在显着相关性。具有分散附件和此转换因子的APS可以在短时间内测量大量样品，从而可以更有效地优化干粉吸入器。通过基于MSLI结果的转换因子计算用于APS测量的颗粒密度设置时，MSLI与APS之间存在显着相关性。具有分散附件和此转换因子的APS可以在短时间内测量大量样品，从而可以更有效地优化干粉吸入器。