Department of Pharmacy and Pharmaceutical Sciences, University of Huddersfield, Huddersfield HD1 3DH, United Kingdom.
Inhalation Consultancy Ltd, Yeadon, Leeds, LS19 7SP, United Kingdom.
Eur J Pharm Sci. 2017 Jun 15;104:180-187. doi: 10.1016/j.ejps.2017.03.035. Epub 2017 Mar 27.
Most patients using dry powder inhalers (DPIs) do not achieve the inhalation parameters recommended for pharmacopoeial in-vitro dose emission testing. The dose emission characteristics of formoterol from an Easyhaler® have been measured using the Andersen Cascade Impactor (ACI) with a maximum inhalation flow (MIF) of 28.3, 60 and 90L/min and inhaled volumes (Vin) of 240, 750, 1500 and 2000mL. The total emitted dose (TED) was significantly higher at 90L/min (p<0.05), but the difference in the TED between low (28.3L/min) and high (90L/min) flow rate was significantly reduced by increasing the Vin. The fine particle dose (FPD) was higher (p<0.05) at 90L/min for all Vin values compared to 28.3 and 60L/min. Similarly the mass median aerodynamic diameter (MMAD) was smaller at 90L/min across all Vin values. Dose emission characteristics were lower at 240mL for both MIFs. The results for 240mL could be due to an insufficient Vin pulled through the ACI or incomplete emptying of the dose metering cup. This study shows that the FPD, %FPF and MMAD were not significantly affected by the vin≥750mL and that an inhaled volume as low as 750mL could be used with the ACI.
大多数使用干粉吸入器（DPIs）的患者无法达到药典规定的体外剂量释放测试吸入参数。本文使用 Andersen Cascade Impactor（ACI）测量了福莫特罗从 Easyhaler®中的剂量释放特性，最大吸入流量（MIF）分别为 28.3、60 和 90L/min，吸入体积（Vin）分别为 240、750、1500 和 2000mL。在 90L/min 时总发射剂量（TED）显著更高（p<0.05），但通过增加 Vin，低（28.3L/min）和高（90L/min）流速之间 TED 的差异显著减小。与 28.3 和 60L/min 相比，所有 Vin 值下 90L/min 时的细颗粒剂量（FPD）更高（p<0.05）。同样，所有 Vin 值下 90L/min 时的质量中值空气动力学直径（MMAD）更小。对于两种 MIF，240mL 的剂量释放特性较低。240mL 的结果可能是由于 ACI 中通过的 Vin 不足或剂量计量杯未完全排空。这项研究表明，当 Vin≥750mL 时，FPD、%FPF 和 MMAD 不受影响，并且可以使用低至 750mL 的吸入体积与 ACI 配合使用。
