Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, 2409 University Ave, A1920, Austin, Texas, 78712, USA.
Escuela De Farmacia, Universidad de Valparaíso, Valparaíso, Chile.
AAPS J. 2018 Jul 12;20(5):84. doi: 10.1208/s12248-018-0241-6.
Although high-speed laser imaging is the current standard to characterize the plume angle of suspension-based pressurized metered dose inhalers (pMDIs), this method is limited by the inability to identify the drug content in a droplet and simulate inhalation flow. The Plume Induction Port Evaluator (PIPE) is a modified induction port for cascade impactors that allows for the calculation of the angle of a plume based on direct drug mass quantification rather than indirect droplet illumination under airflow conditions. The objective of this study was to investigate the use of the PIPE apparatus to evaluate the effect of airflow on the Mass Median Plume Angle (MMPA) of commercially available suspension-based pMDIs (Ventolin® HFA, ProAir® HFA, and Proventil® HFA). Deposition patterns within PIPE were log-normally distributed allowing for the calculation of the MMPA for the three suspension products. Mass-based plume angles were significantly smaller (narrower angle) when inhalation airflow was used compared to no flow conditions (reduction of MMPA was 8, 16, and 13% for Ventolin® HFA, ProAir® HFA, and Proventil® HFA, respectively). Additionally, new parameters for characterizing plume geometry were calculated (MMPA ex-actuator and plume orientation). Mass-based plume angles of the suspension-based pMDI formulations were highly reproducible and demonstrated the effect of inhalation flow rate. These results suggest that plume geometry tests should be evaluated under flow conditions which is not possible using current methodologies. Graphical Abstract ᅟ.
虽然高速激光成像是表征悬浮型压力定量吸入器（pMDI）喷雾角的当前标准，但该方法受到无法识别液滴中的药物含量和模拟吸入气流的限制。喷雾诱导端口评估器（PIPE）是级联撞击器的改良诱导端口，它允许根据直接药物质量定量而不是在气流条件下间接液滴照明来计算喷雾的角度。本研究的目的是研究使用 PIPE 装置评估气流对市售悬浮型 pMDI（万托林® HFA、普米克® HFA 和喘乐宁® HFA）的质量中值喷雾角（MMPA）的影响。PIPE 内的沉积模式呈对数正态分布，允许计算三种悬浮产品的 MMPA。与无气流条件相比，吸入气流时的基于质量的喷雾角明显更小（角度更窄）（万托林® HFA、普米克® HFA 和喘乐宁® HFA 的 MMPA 分别降低了 8%、16%和 13%）。此外，还计算了表征喷雾几何形状的新参数（喷雾器出口处的 MMPA 和喷雾方向）。悬浮型 pMDI 制剂的基于质量的喷雾角具有高度重现性，并证明了吸入气流速率的影响。这些结果表明，在当前方法不可能的情况下，应在气流条件下评估喷雾几何形状测试。
