一种O/W型微乳液纳米载体的制备及其对大麻二酚包覆的性能研究

Preparation of an O/W microemulsion nano-carrier and its performance in cannabidiol encapsulation

为了获得一种稳定的活性物包覆的纳米载体,以PolyAquol LW为非离子表面活性剂,丁二醇为助表面活性剂,霍霍巴油为油相;采用滴油法,以丁达尔现象作为澄清透明微乳液临界点判断的依据,绘制了PolyAquol LW/丁二醇/霍霍巴油/H2O的水包油(O/W)型微乳液的伪三元体系相图。根据伪三元相图,确定了水包油型微乳液的最佳制备条件;以脂溶性大麻二酚作为模型活性物,制备了大麻二酚微乳液。研究了大麻二酚微乳液的表面张力、粒径分布以及透光率,考察了温度、高速离心对大麻二酚微乳液稳定性的影响。结果表明:当PolyAquol LW/丁二醇质量比(ζ)为2∶1,PolyAquol LW质量分数为1%时,霍霍巴油最大载油量的质量分数为9.09%;以此微乳液为载体包覆大麻二酚时,大麻二酚最大负载量可达1.62 mg/mL,此时表面张力降低至41.2 mN/m;稳定性研究结果表明:微乳液经过10 000 r/min离心20 min或者60℃放置3 h,依然能稳定存在且不分层,透光率几乎不变。本研究以微乳液为载体可以实现化妆品活性物的纳米包覆,在化妆品的开发与应用方面具有重要价值。

To obtain a stable nanocarrier suitable for the encapsulation of active substances, an oil-in-water(O/W) microemulsion was prepared with Poly Aquol LW as a non-ionic surfactant, butanediol as the cosurfactant, and jojoba oil as the oil phase. Pseudoternary phase diagram was plotted by the oil titration method, and the critical point of the as-obtained microemulsion was determined by the Tyndall effect. According to the pseudo-ternary phase diagram of the O/W microemulsion, the optimum preparation condition of the O/W microemulsion was determined. Then the oil-soluble cannabidiol(CBD) was selected as model active substance to prepare the cannabidiol microemulsion. The surface tension, particle size distribution and transmittance of the CBD microemulsion were measured. The effects of temperature and high-speed centrifugation on the stability of the CBD microemulsion were also investigated. The results showed that the maximum loading of jojoba oil was 9.09% when the mass ratio of PolyAquol LW/butanediol(ζ) was 2∶1 and the mass fraction of PolyAquol LW was 1%;when such microemulsion was used as the carrier, the maximum loading of CBD could reach 1.62 mg/mL, and the minimum surface tension was 41.2 mN/m. The stability results showed that the CBD microemulsion could still remain stable without phase separation, and the light transmittance almost remained unchanged after centrifugation at 10 000 r/min for 20 min or being placed at-18 and 60 ℃ for 3 h, indicative of the excellent stability of CBD microemulsion. This work suggests that this microemulsion as a nano-carrier can realize the effective encapsulating of active substances in cosmetics, which has important value in the development and application of cosmetic products.