Influence of particle size and patient dosing technique on lung deposition of HFA-beclomethasone from a metered dose inhaler
Influence of particle size and patient dosing technique on lung deposition of HFA-beclomethasone from a metered dose inhaler
复制标题
DOI:
10.1089/jam.2005.18.379
复制
发表时间:
2005-12-01
期刊:
影响因子:
--
通讯作者:
Boudreau, RJ
中科院分区:
文献类型:
--
作者:
Leach, CL;Davidson, PJ;Boudreau, RJ
The objective of this study was to determine the lung delivery of HFA-134a-beclomethasone dipropionate (HFA-BDP) from a breath-activated inhaler (QVAR (TM) Autohaler (TM)) compared with proper and improper press and breathe (QVAR (TM) P&B) metered dose inhaler (MDI) technique. The hypothesis was that that the smaller particles of BDP from HFA-BDP would stay suspended longer in the inspiratory air of patients and thus reduce the deleterious eff- ects of inhaler disco ordination. The study was an open label, four period, cross-over design. Asthmatic patients (n = 7) with a history of asthma symptoms, an FEV-1 of > 70% of predicted normal, and a history of reversibility to a beta-agonist of >= 12% were utilized. BDP was radiolabeled with technetium-99m and delivered from the QVAR Autohaler or QVAR P&B device in patients trained to reproducibly utilize coordinated and discoordinated P&B MDI technique. Patients using Autohaler MDI exhibited 60% lung deposition of BDP. Patients using coordinated technique with the P&B MDI exhibited 59% lung deposition. Patients trained to consistently actuate the P&B MDI before inhaling exhibited 37% lung deposition. Patients trained to consistently actuate the P&B MDI late in the inspiration (i.e., 1.5 sec into a 3-sec inspiration) exhibited 50% lung deposition. In conclusion, the breath-activated Autohaler automatically provided optimal BDP lung deposition of 60%. Patients with good P&B MDI technique also received optimal lung deposition of 59%. The degree of lung deposition was decreased as patients demonstrated poor inhaler technique. However patients with poor technique still received a large lung dose of BDP (i.e., >= 37%) compared with lung deposition values of 4-7% for CFC-BDP MDIs previously published and confirmed in this study.