Barry P W, O'Callaghan C
Dept of Child Health, University of Leicester, UK.
Eur Respir J. 1994 Sep;7(9):1707-9. doi: 10.1183/09031936.94.07091707.
We wanted to determine the amount of salbutamol available in respirable particles from the Volumatic spacer device after one, two or five actuations of a metered-dose inhaler into the spacer prior to analysis. A glass multistage liquid impinger was used to determine particle size. Aerosol was sampled after one, two or five actuations from a metered-dose inhaler into a Volumatic spacer. Each experiment was repeated four times. The amount of salbutamol recovered per actuation in particles less than 5 microns (mean and 95% confidence intervals) was: 54.3 micrograms (48.3-60.1) after one actuation; 42.4 micrograms (38.2-46.5) after two actuations, and 20.7 micrograms (17.5-23.9) after five actuations. We conclude that multiple actuations of salbutamol into the Volumatic spacer do not linearly increase the amount of drug available for inhalation. To maximize drug delivery, single actuations should be used prior to inhalation. In comparative studies of drugs and dosages, it must be remembered that the amount of drug delivered is not the same as that administered.
我们想要确定在分析之前，将定量吸入器向Volumatic储雾罐内按压1次、2次或5次后，可吸入颗粒中沙丁胺醇的含量。使用玻璃多级液体冲击器来测定颗粒大小。从定量吸入器向Volumatic储雾罐内按压1次、2次或5次后采集气雾剂样本。每个实验重复4次。每次按压后在小于5微米的颗粒中回收的沙丁胺醇量（均值和95%置信区间）为：按压1次后为54.3微克（48.3 - 60.1）；按压2次后为42.4微克（38.2 - 46.5）；按压5次后为20.7微克（17.5 - 23.9）。我们得出结论，向Volumatic储雾罐内多次按压沙丁胺醇并不会使可供吸入的药物量呈线性增加。为了使药物递送最大化，吸入前应使用单次按压。在药物和剂量的对比研究中，必须记住递送的药物量与给药量并不相同。
