Thies J, Müller B W
Christian Albrecht University, Kiel, Germany.
Eur J Pharm Biopharm. 1998 Jan;45(1):67-74. doi: 10.1016/S0939-6411(97)00124-0.
Polymer microparticles were produced by means of the aerosol solvent extraction system. A solution of 3% w/w poly(L-lactic acid) in dichloromethane was sprayed into supercritical or near critical carbon dioxide gas phase. The mean particle size by volume moderately depended on the nozzle diameter and the spraying pressure used. When the polymer solution was saturated with carbon dioxide up to 5.0 MPa, the particle size and morphology of the particles were unchanged and the product was less agglomerated. Microparticles with mean diameters from 6 to 50 microns were achieved by decreasing the carbon dioxide density from 690 to 250 kg/m3. The surface structure of the particles sprayed in low density carbon dioxide showed cracks and holes. All other particles were non-porous with a smooth surface.
聚合物微粒通过气溶胶溶剂萃取系统制备。将3%（重量/重量）的聚（L-乳酸）二氯甲烷溶液喷入超临界或近临界二氧化碳气相中。体积平均粒径适度依赖于所使用的喷嘴直径和喷雾压力。当聚合物溶液在高达5.0MPa的压力下用二氧化碳饱和时，颗粒的粒径和形态不变，且产物的团聚较少。通过将二氧化碳密度从690kg/m³降低到250kg/m³，可得到平均直径为6至50微米的微粒。在低密度二氧化碳中喷雾得到的颗粒表面结构呈现出裂缝和孔洞。所有其他颗粒均为无孔且表面光滑。
