气体抗溶剂法制备乙基纤维素微细颗粒

利用超临界流体制备微细颗粒是一门新兴的技术，将其中的气体抗溶剂（GAS）法首次应用于制备乙基纤维素微粒，在系统的近临界和超临界范围进行了较为详细的实验研究.在实验范围内，制得微粒的平均粒径为2～15 μm.研究得到温度、压力、不同有机溶剂对微粒粒径及其分布的影响，并应用相平衡知识对结果进行了分析和讨论.此研究为制备粒径较小，具有缓释、靶向、黏附等功能的乙基纤维素含药微粒做了准备.

Microparticle formation of ethyl-cellulose with gas antisolvent process

The gas antisolvent (GAS) process makes use of the ability of gases to dissolve in organic liquids and to lower the solvent power of the liquid for the solutes in solution, thus causing the solids to precipitate.Ethyl-cellulose(EC) is the ramification of cellulose.It is the first time to use the gas antisolvent process to produce EC microparticles,which would be mainly used as a hydrophobic coating material or matrix former for modifying the release of drugs from oral dosage forms.In the experimental conditions, different size particles of EC, with mean diameters ranging from 2 μm to 15 μm, were obtained.Several parameters, such as pressure, temperature and different organic solvents,were investigated.The results showed that the mean particle size increased as the temperature of the particle formation vessel increased;while the particle size and its distribution decreased as the pressure of the particle formation vessel increased.The acetone solution of EC could make smaller particles than the ethanol solution.This work is the first step to make sustained releasing, target, adhesive and drug containing EC micropariticles.