Preparation of Liposome Particle of Atractylone by Supercritical Carbon Dioxide Process

The liposome particle entrapping atractylone extracted from Atractylodes macrocephala Koidz.was prepared and characterized. The liposome suspension of atractylone was formed by supercritical carbon dioxide (SC-CO2) expansion process and was dried by vacuum freezing. The physicochemical properties of the liposome particle including microstructure, size, entrapment efficiency and drug loading content were measured. The liposome formation could be controlled by adjusting the processing conditions such as pressure, temperature of SC-CO2 and mole fraction of ethanol in SC-CO2 [ x (CH3CH2OH)]. The entrapment efficiency, loading content, and average size of liposome particle were 83.1％, 5.1％ and 506.5nm respectively under the optimum conditions of 30MPa，338K and x (CH3CH2OH) = 15％.The liposome particle presented good performance of redispersion to liposomal suspension. The physicochemical properties of liposome particle including entrapment efficiency, dissolution rate and stability complied with the provisions of Chinese pharmacopoeia. The results show the liposome particle can be used as an solid immediate for hepatic target of drugs.