Determination methods for in vitro deposition of metered dose inhalers: Differences of three impactors / 国际药学研究杂志

ABSTRACT

Objective To analyze and compare fine particle fraction (FPF) and particle size distribution (PSD) measured by twin-stage impactor(TSI), Andersen cascade impactor (ACI) and next generation pharmaceutical impactor(NGI). Methods Selfmade metered dose inhaler(MDI) of fluticasone propionate was selected as the model drug, and the FPF and PSD were determined by TSI, ACI and NGI. Results The device of TSI was simple, and fine particle drug dose with less than 6.4 micrometer aerodynamic diameter size was acquired quickly, and the recovery rate was relatively high under the good seal, but aerodynamic diameter distribution was not obtained. In contrast, both the aerodynamic diameter and particle size distribution were obtained with ACI and NGI. Different from ACI, for NGI it was not necessary to wash the sieves, although NGI is heavy. So, the operation of NGI is simpler. Conclusion NGI can be chosen as the priority for the determination of the aerodynamics related parameters.