Rau J L, Torniainen M
Georgia State University, Atlanta 30303, USA.
Respir Care. 2000 Mar;45(3):320-6.
Combining a positive expiratory pressure (PEP) device with inhalation of albuterol via metered dose inhaler (MDI) may improve drug delivery to the lung, but may also affect dose availability.
Determine the effect of interposing a PEP device on dose availability of albuterol via MDI and reservoir with either a chlorofluorocarbon (CFC) or hydrofluoroalkane (HFA) propellant.
MDI dose availability of CFC albuterol (Proventil) and HFA albuterol (Proventil HFA) using an Aerosol Cloud Enhancer (ACE) reservoir with and without a PEP device (TheraPEP) attached was determined. Drug availability was assessed using an Andersen 8-stage cascade impactor operated at 28.3 +/- 0.5 L/min. The PEP device was inserted between the reverse-firing ACE and the United States Pharmacopeia induction throat. Drug collected on impactor plates was analyzed spectrophotometrically at 276 nm, and the fine particle fraction was determined as the mass of drug < 4.7 microns.
With CFC albuterol, total dose and drug mass < 4.7 microns (means and standard deviations) for the MDI-ACE alone were 44.4 +/- 7.7 micrograms and 33.4 +/- 2.2 micrograms, respectively, and for the MDI-ACE with TheraPEP were 50.1 +/- 6.4 micrograms and 39.8 +/- 14.3 micrograms, respectively. With HFA-albuterol sulfate, total drug and drug mass < 4.7 microns for the MDI-ACE alone, expressed as base drug, were 41.7 +/- 4.2 micrograms and 35.2 +/- 6.3 micrograms, respectively, and for the MDI-ACE with TheraPEP were 48.9 +/- 8.0 micrograms and 44.2 +/- 6.2 micrograms, respectively. There was no significant difference in dose availability between the MDI-ACE alone and with the PEP device attached (Wilcoxon signed-rank test, p > 0.05), for either CFC or HFA albuterol.
Interposing the TheraPEP device at the MDI-ACE outlet does not change total dose, drug mass < 4.7 microns, or mass median aerodynamic diameter of MDI albuterol, with either CFC or HFA propellants.
将呼气末正压（PEP）装置与通过定量吸入器（MDI）吸入沙丁胺醇相结合，可能会改善药物向肺部的递送，但也可能影响剂量的可利用性。
确定在使用含氯氟烃（CFC）或氢氟烷烃（HFA）推进剂的MDI和储雾罐中插入PEP装置对沙丁胺醇剂量可利用性的影响。
测定了使用带有和不带有PEP装置（TheraPEP）的气雾剂云雾增强器（ACE）储雾罐时，CFC沙丁胺醇（喘乐宁）和HFA沙丁胺醇（信必可都保）的MDI剂量可利用性。使用在28.3±0.5升/分钟运行的Andersen 8级级联撞击器评估药物可利用性。将PEP装置插入反向喷射的ACE和美国药典诱导喉部之间。收集在撞击器板上的药物在276纳米处用分光光度法进行分析，细颗粒部分被确定为粒径小于4.7微米的药物质量。
对于CFC沙丁胺醇，单独使用MDI-ACE时的总剂量和粒径小于4.7微米的药物质量（平均值和标准差）分别为44.4±7.7微克和33.4±2.2微克，而使用带有TheraPEP的MDI-ACE时分别为50.1±6.4微克和39.8±14.3微克。对于硫酸HFA-沙丁胺醇，单独使用MDI-ACE时以碱基药物表示的总药物和粒径小于4.7微米的药物质量分别为41.7±4.2微克和35.2±6.3微克，而使用带有TheraPEP的MDI-ACE时分别为 48.9±8.0微克和44.2±6.2微克。对于CFC或HFA沙丁胺醇，单独使用MDI-ACE和连接PEP装置时，剂量可利用性没有显著差异（Wilcoxon符号秩检验，p>0.05）。
在MDI-ACE出口处插入TheraPEP装置不会改变使用CFC或HFA推进剂时MDI沙丁胺醇的总剂量、粒径小于4.7微米的药物质量或质量中位空气动力学直径。
