Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Ant. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
Int J Pharm. 2012 Nov 1;437(1-2):242-9. doi: 10.1016/j.ijpharm.2012.08.020. Epub 2012 Aug 19.
Developments in high dose dry powder aerosol delivery will increasingly challenge the applicability of currently used aerosol characterisation techniques. With cascade impaction analysis bounce effects can negatively influence stage collection efficiency, especially with increasing impactor loads. In this study the suitability of the multi stage liquid impinger (MSLI) and the Next Generation Impactor (NGI) for the characterisation of dry powder aerosols containing up to 50mg of drug is evaluated. The occurrence of bounce effects is quantitatively assessed by comparison with data obtained from laser diffraction analysis. The liquid based impaction surfaces of the MSLI largely prevent bounce effects, but the low number of cut-off values associated with this impactor hinders accurate data interpretation. With the NGI, a standard high viscosity plate coating insufficiently reduces bounce effects, causing the fraction <1 μm to be higher than what can maximally be expected based on the primary particle size distribution (PSD) obtained from RODOS dispersion. With this type of impactor, the use of solvent soaked filters as impaction surface is necessary to eliminate bounce effects.
高剂量干粉气溶胶输送的发展将越来越挑战目前使用的气溶胶特性分析技术的适用性。在级联撞击分析中，反弹效应会对阶段收集效率产生负面影响，尤其是在撞击器负荷增加的情况下。本研究评估了多阶段液体撞击器（MSLI）和下一代撞击器（NGI）在对含有高达 50mg 药物的干粉气溶胶进行特性分析方面的适用性。通过与激光衍射分析获得的数据进行比较，定量评估了反弹效应的发生情况。MSLI 的液体撞击表面在很大程度上防止了反弹效应，但与该撞击器相关的截断值数量较少，阻碍了准确的数据解释。对于 NGI，标准的高粘度板涂层不足以减少反弹效应，导致<1μm的部分高于根据 RODOS 分散获得的原始粒径分布（PSD）最大可预期值。对于这种类型的撞击器，需要使用浸有溶剂的过滤器作为撞击表面来消除反弹效应。
