效应面法优化葛根素纳米晶自稳定Pickering乳液的稳定性

Stability optimization of puerarin nanocrystalline self-stabilizied Pickering emulsion by response surface methodology

研制葛根素纳米晶自稳定Pickering乳液(puerarin nanocrystalline self-stabilized Pickering emulsion,Pu-NSSPE),采用Box-Behnken设计效应面法优化处方以提高其稳定性,研究药物浓度、水相p H和水油体积比对乳液的分层指数、乳液层的药物含量和乳滴粒径变化的影响。结果显示,当葛根素浓度为0.5%,水相p H为9,水油体积比为9时,能得到最稳定的Pu-NSSPE,乳滴粒径为(12.70±1.17)μm,乳液层的药物浓度为(4.49±0.21)g·L-1,室温放置6个月后均无明显变化,稳定性好。采用扫描电镜、激光共聚焦显微镜和荧光倒置显微镜对乳滴结构进行表征,结果显示葛根素纳米晶能吸附于油滴界面形成稳定的球状核-壳结构,这可能是Pu-NSSPE能够长期稳定的微观结构原因。

A new Pickering emulsion, puerarin nanocrystalline self-stabilized Pickering emulsion （Pu-NSSPE） was developed. Box-Behnken design was used for optimizing the preparation formulation of Pu-NSSPE to improve its stability, and the effects of concen- tration of puerarin, volume ratio of water to oil, and pH value of water phase on the stratification index of emulsion, droplet size and drug concentration in emulsion were investigated. Results showed that the optimized Pu-NSSPE could be prepared with the concentra- tion of puerarin of 0. 5%, the volume ratio of water to oil of 9：1 and the pH of water of 9. The size of emulsion droplet of optimized Pu- NSSPE was （ 12. 70 ± 1.17） μm and the drug content was （4. 49 ±0. 21 ） g · L-1. The above indexes had no significant changes with- in the storage of 6 months at room temperature, indicating good stability. Microstructure characterizations by scanning electron micro- graph, confocal laser scanning microscope and fluorescence microscope showed that the optimized Pu-NSSPE had a stable core-shell structure of emulsion droplet formed by the adsorption of puerarin nanocrystallines at the surface of oil droplets, which may be the mi- crostructure reason for the long stability of Pu-NSSPE.