Abstract:

Nanostructured lipid carrier (NLC) coated with two sunscreens, benzophenone-3 (BP-3) and octyl methoxycinnamate (OMC), was prepared by high pressure homogenization. The effects of the total oil content, liquid lipid content, sunscreen content, as well as the emulsifier type and dosage on the particle size, zeta potential and entrapment efficiency of NLC were investigated by single-factor experiments, and the technical formula was optimized. Moreover, the effects of electrolyte type and concentration as well as the amount of emulsifier on the aggregation behaviors of NLC were further investigated and the dynamic model was established. The results show that the electrolyte can compress the electric double layer of the colloid system and decrease the zeta potential, which also aggravate the aggregation and binding between the nanoparticles. The critical coagulation concentrations of NLC samples in the inorganic electrolyte solutions of NaCl and CaCl₂ were 538.2 and 95.8 mmol·L^-1, respectively. And the aggregation rate of NLC in the solution of CaCl₂ is faster than that in NaCl solutions. Besides, the proper amount of the emulsifier is also helpful to maintain the stability of the NLC system.

Key words: nanostructured lipid carrier, aggregation, kinetics, preparation, sunscreen, model

摘要：

采用高压均质法制备包覆二苯酮-3（BP-3）和对甲氧基肉桂酸辛酯（OMC）两种紫外线吸收剂的纳米结构脂质载体（NLC），并通过单因素实验探究了总油相含量、液体脂质用量、防晒剂含量、乳化剂种类及其用量对NLC粒径、ζ电位和包封率的影响，并优化了工艺配方。此外，还考察了电解质的种类、浓度以及乳化剂用量对NLC聚集行为的影响并建立了聚集动力学模型。结果表明，电解质的存在可以压缩胶体体系的双电层，导致ζ电位降低，加剧纳米粒之间的聚集结合。NLC样品在电解质NaCl和CaCl₂存在下的临界聚沉浓度分别为538.2和95.8 mmol·L^-1，且在CaCl₂溶液中的聚集速度比NaCl溶液中更快，适量的乳化剂对维持NLC体系的稳定性具有重要作用。

关键词: 纳米结构脂质载体, 聚集作用, 动力学, 制备, 防晒剂, 模型