卵磷脂微乳的制备与理化性质考察

目的：对25℃各卵磷脂系统中微乳的形成区域以及微乳理化性质随系统中各组分的变化情况进行研究。方法：卵磷脂作表面活性剂，短链醇类作助表面活性剂，采用不同油相考察相图中油包水型微乳形成区域的变化；选择不同处方组分的微乳测定微乳理化性质。结果：各个系统均可形成油包水型微乳，室温下放置数月未见分层。卵磷脂/醇质量比(K_m)与水相量对微乳的粘度有显著影响；电导率随着水相含量增加而增大；微乳的粒径随着体系中水相的增加而增大。结论：K_m较大，水相含量适中的微乳体系较为适合制备药物载体。

FORMATION AND PHYSICAL-CHEMISTRY CHARACTERIZATION OF THE PHOSPHATIDYCHOLINE MICROEMULSIONS

AIM：To study the formation of microemulsion phases at 25℃ for systems containing soybean phosphatidylcholine and the effect of formulation variables on the physical-chemistry characterization of microemulsion. METHODS: High purity lecithin (PC>96%) was used as surfactant, several short chain alcohols (i.e. ethanol, n-propanol, n-butanol, n-pentanol) were investigated as cosurfactant and isopropyl myristate as oil. Viscosity, conductance, refraction and mean droplet diameters of the microemulsions were measured. RESULTS: In each system studied, w/o microemulsion could be observed along the surfactant /oil axis. All microemulsions were stable at room temperature for several months. The physicochemical properties of lecithin microemulsions were influenced by the formulation variables: conductance and mean droplet diameter increased as the proportion of water increased; the proportion of water and the ratio of lecithin/ethanol (K_m) showed predominant influence on the viscosity of the microemulsion. CONCLUSION: The extent of the regions of the microemulsion was dependent upon the nature of the cosurfactant and the oil and also the lecithin/cosurfactant mixing ratio (K_m). The IPM/PC/ethanol/water system was chosen to produce O/W microemulsions used for drug delivery. The formulation that has relatively large K_m and medium proportion of water was better to be used in drug delivery system.