中文摘要：

引言干粉吸入剂是将一种或多种药物制成一定范围的微小颗粒,经特殊的给药装置使药物以粉雾状进入呼吸道和肺部,发挥局部或全身的作用。影响吸入的因素主要有粒径大小、形态、分散性和吸湿性等特性,其中药物的粒径大小和分布是影响DPI[1-2]

英文摘要：

As model drug,beclomethasone dipropionate（BDP）nanoparticles were prepared by using the antisolvent precipitation method in a T-junction microchannel.The influence of surfactant on particle morphology,as well as the influences of surfactant concentration,BDP solution flow rate,antisolvent flow rate,BDP solution concentration and precipitation temperature on particle size were explored.The results indicated that the morphology of BDP was spherical with the addition of surfactant（HPMC）.Besides,the particle size decreased with decreasing BDP solution flow rate,increasing antisolvent flow rate and decreasing precipitation temperature.However,with the increase of BDP concentration,particle size reached a minimum.BDP nanoparticles with an average size of 200—260 nm and narrow size distribution could be prepared under the following conditions： BDP solution flow rate of 4 ml·min-1,antisolvent flow rate of 80 ml·min-1,solution concentration of 0.03 g·ml-1.Furthermore,crude BDP and nanosized BDP were characterized by scanning electronic microscopy（SEM）,X-ray diffraction（XRD）,Fourier transform infrared spectrophotometry（FTIR）,and surface area analyzer.The results showed that the precipitated BDP without HPMC was crystalline while the precipitated BDP with HPMC was completely amorphous.In addition,the as-prepared BDP had the same molecular structure as raw drug,and had a specific surface area 2 times as high as that of raw drug.T-junction microchannel would become a high-efficiency,low-cost technology platform of preparing nanodrugs.