Zhang J X, Zhu K J
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
J Microencapsul. 2004 Nov;21(7):775-85. doi: 10.1080/02652040400008465.
A modified double emulsion technique was adopted to prepare bovine serum albumin (BSA) loaded poly (D,L-lactic-co-glycolic acid) (PLGA) microspheres. In the formulations, polysorbates (Tween) such as Tween20, Tween40 or Tween80, instead of frequently used poly (vinyl alcohol) (PVA), was used as the emulsifier. Microspheres with porous surface, large particle size, low microsphere yield (approximately 65.4%) and BSA entrapment efficiency (approximately 25.2%) were obtained when Tween80 aqueous solution alone was used as the outer aqueous phase. However, microspheres with smooth surface, high yield and BSA entrapment efficiency could be produced successfully by introducing sodium chloride or glucose into the outer aqueous phase. Adding 5.0%(w/v) sodium chloride into the continuous phase led to increase in microsphere yield and BSA entrapment efficiency from 65.4% and 25.2% to approximately 100% and 76.6%, respectively. Microsphere yield and BSA entrapment efficiency increased from 64.5% and 25.2% to 97.2% and 89.3%, respectively, when 15.0%,(w/v) glucose was added into the continuous phase. In constrast to the microspheres prepared in the presence of additive, a more marked burst release was observed for microspheres prepared without additive in the continuous phase, which may be attributed to the porous morphology of the latter.
采用改良的双乳液技术制备负载牛血清白蛋白（BSA）的聚（D，L-乳酸-乙醇酸共聚物）（PLGA）微球。在这些制剂中，使用吐温20、吐温40或吐温80等聚山梨酯（吐温）代替常用的聚乙烯醇（PVA）作为乳化剂。当单独使用吐温80水溶液作为外水相时，得到了具有多孔表面、大粒径、低微球产率（约65.4%）和BSA包封率（约25.2%）的微球。然而，通过在外水相中引入氯化钠或葡萄糖，可以成功制备出表面光滑、高产率和BSA包封率的微球。向连续相中加入5.0%（w/v）氯化钠导致微球产率和BSA包封率分别从65.4%和25.2%提高到约100%和76.6%。当向连续相中加入15.0%（w/v）葡萄糖时，微球产率和BSA包封率分别从64.5%和25.2%提高到97.2%和89.3%。与在添加剂存在下制备的微球相比，在连续相中无添加剂制备的微球观察到更明显的突释，这可能归因于后者的多孔形态。
