Berg E, Madsen J, Bisgaard H
Pharmaceutical and Analytical R&D, Analytical Chemistry, Astra Draco AB, Lund, Sweden.
Eur Respir J. 1998 Aug;12(2):472-6. doi: 10.1183/09031936.98.12020472.
The performance of pressurized metered dose inhalers (pMDIs) and spacers in correct dose recommendations is important, but limited information on dose delivery and fine-particle dose from different combinations of spacers and pMDIs is available. In this study, three combinations of spacers and pMDIs were investigated: NebuChamber and AeroChamber with budesonide pMDI and Babyhaler with fluticasone propionate pMDI. Doses were withdrawn onto a filter either with a breathing simulator (dose to ventilator) or with constant flow (maximal dose). The fine-particle dose was assessed with a cascade impactor (Andersen Sampler). The effect of repeated use and cleaning of the spacers on the passive fallout of aerosol within the spacers was determined by evacuating the dose on a filter 2, 5, 10 and 30 s after actuating the spray. The drugs were quantified by liquid chromatography. The NebuChamber delivered the highest doses, both maximal dose and dose to ventilator. The recovered doses (means+/-SD) were 55+/-6% and 51+/-2%, respectively, of the delivered dose from the pMDI. The corresponding results for the Babyhaler were 41+/-7% and 24+/-4% and for the Aerochamber 27+/-3% and 17+/-3%. The passive fallout of aerosol, determined as half-life (t1/2) was around approximately 30 s for the NebuChamber, 9-15 s for the Babyhaler and approximately 10 s for the AeroChamber. The present study confirms that there are significant differences in dose output from different combinations of pressurized metered dose inhalers and spacers, with the NebuChamber giving the highest dose, both as delivered dose and in droplets <4.7 microm. Interactions with the spacer material, dead space in the inspiratory line and entrainment of air during inhalation due to inefficient valve control could account for these differences.
压力定量吸入器（pMDIs）和储雾罐在正确剂量推荐方面的性能很重要，但关于不同储雾罐和pMDIs组合的剂量输送和细颗粒剂量的信息有限。在本研究中，对三种储雾罐和pMDIs的组合进行了研究：使用布地奈德pMDI的NebuChamber和AeroChamber，以及使用丙酸氟替卡松pMDI的Babyhaler。剂量通过呼吸模拟器（输送至呼吸机的剂量）或恒流（最大剂量）抽取到滤器上。用级联冲击器（Andersen采样器）评估细颗粒剂量。通过在启动喷雾后2、5、10和30秒将剂量抽取到滤器上来确定储雾罐重复使用和清洁对储雾罐内气溶胶被动沉降的影响。通过液相色谱对药物进行定量。NebuChamber输送的剂量最高，无论是最大剂量还是输送至呼吸机的剂量。回收剂量（平均值±标准差）分别为pMDI输送剂量的55±6%和51±2%。Babyhaler的相应结果为41±7%和24±4%，Aerochamber为27±3%和17±3%。气溶胶的被动沉降，以半衰期（t1/2）确定，NebuChamber约为30秒，Babyhaler为9 - 15秒，AeroChamber约为10秒。本研究证实，不同压力定量吸入器和储雾罐组合的剂量输出存在显著差异，NebuChamber的剂量最高，无论是输送剂量还是<4.7微米的液滴剂量。与储雾罐材料的相互作用、吸气管路中的死腔以及由于阀门控制效率低下导致的吸入过程中的空气夹带可能是造成这些差异的原因。
