中文摘要：

超临界反溶剂过程是近年来提出的一种制备纳微米粉体材料的新方法．实验以乙醇为有机溶剂，CO2为反溶剂，利用连续式超临界反溶剂过程制备四环素超细微粒．研究了操作压力、温度、浓度、喷嘴内径等操作参数对制备的四环素超细微粒形态、粒径及粒径分布的影响．实验结果表明：采用乙醇作为有机溶剂，在压力15．0MPa、温度35℃、溶液浓度5mg／mL及喷嘴内径75μm实验条件下可得到较理想的实验结果，制备出的四环素超细微粒平均直径为20～40nm．

英文摘要：

Supercritical antisolvent （SAS） process, which has been developed recently, is a new method to produce micro- and nano-particles. A continuous apparatus to conduct SAS process is applied to produce tetracycline micro-particles. Ethanol is used as organic solvent and CO2 as antisolvent. The effects of pressure, temperature, solution concentration and nozzle diameter on the morphology, size and size distribution of the particles are studied for the tetracycline-ethanol-CO2 system. The experimental results show that tetracycline particles with diameters ranging from 20 nm to 40 nm can be prepared by SAS process successfully under the conditions of the pressure 15.0 MPa, temperature 35 ℃, solution concentration 5 mg/mL and nozzle diameter 75 μm.