Barry P W, O'Callaghan C
Dept of Child Health, University of Leicester, UK.
Eur Respir J. 1997 Jun;10(6):1345-8. doi: 10.1183/09031936.97.10061345.
Metered-dose inhalers (MDIs) are currently being reformulated to contain hydrofluoroalkanes (HFAs), which do not damage the Earth's ozone layer. As different formulations of inhaled drugs may behave differently when used with spacer devices, we wished to determine the amount of salbutamol available for inhalation from a conventional metered-dose inhaler (Ventolin) and a new HFA-containing formulation (Airomir), when used with two different spacers. A glass multistage liquid impinger was used to determine the amount of salbutamol delivered from the inhalers used with the Aerochamber and the Nebuhaler spacer devices. High speed video-recordings of inhaler actuation into air were made, and the speed of the aerosol and the aerosol cloud volume were measured. More salbutamol in small particles (<5 microm) was delivered from the Airomir MDI than the Ventolin MDI, when used with the Aerochamber (40.4 (95% confidence interval (95% CI) 31.2-49.6) versus 19.5 (19.0-20.0) microg) and the Nebuhaler (42.1 (36.3-47.9) versus 24.6 (23.3-25.8) microg). The aerosol cloud from the Airomir MDI was slower than the Ventolin aerosol, and 60 ms after actuation had travelled 186 mm, whereas the Ventolin aerosol had travelled 320 mm. At the same time, the Airomir aerosol occupied a smaller volume than the Ventolin MDI (251 (213-288) versus 695 (608-782) cm3). The hydrofluoroalkane formulation delivers more salbutamol than the conventional formulation when used either with the Aerochamber or Nebuhaler spacer. This may be because less drug is deposited in the spacer from the hydrofluoroalkane formulation, which is emitted from the metered-dose inhaler at a slower speed and occupies a smaller volume than the conventional formulation. The observed difference in drug delivery may be important for patients changing formulations, and in severe asthma, where high doses of salbutamol may be administered through a spacer.
定量吸入器（MDIs）目前正在重新配方，以含有氢氟烷烃（HFAs），这种物质不会破坏地球臭氧层。由于吸入药物的不同配方与储雾罐装置一起使用时可能表现不同，我们希望确定使用两种不同储雾罐时，从传统定量吸入器（万托林）和含氢氟烷烃的新配方（爱全乐）中可吸入的沙丁胺醇量。使用玻璃多级液体冲击器来确定与Aerochamber和Nebuhaler储雾罐装置一起使用时吸入器递送的沙丁胺醇量。对向空气中启动吸入器的过程进行了高速视频记录，并测量了气雾剂的速度和气雾云体积。与Aerochamber一起使用时，爱全乐MDI递送的小颗粒（<5微米）中的沙丁胺醇比万托林MDI更多（40.4（95%置信区间（95%CI）31.2 - 49.6）对19.5（19.0 - 20.0）微克），与Nebuhaler一起使用时也是如此（42.1（36.3 - 47.9）对24.6（23.3 - 25.8）微克）。爱全乐MDI的气雾云比万托林气雾剂慢，启动后60毫秒移动了186毫米，而万托林气雾剂移动了320毫米。同时，爱全乐气雾剂所占体积比万托林MDI小（251（213 - 288）对695（608 - 782）立方厘米）。当与Aerochamber或Nebuhaler储雾罐一起使用时，氢氟烷烃配方递送的沙丁胺醇比传统配方更多。这可能是因为从氢氟烷烃配方中较少药物沉积在储雾罐中，其从定量吸入器中喷出的速度较慢，且所占体积比传统配方小。观察到的药物递送差异对于更换配方的患者以及在严重哮喘中可能很重要，在严重哮喘中可能通过储雾罐给予高剂量的沙丁胺醇。
