Netto MPharm Gladyston, Jose Jobin
Department of Pharmaceutics, N.G.S.M. Institute of Pharmaceutical Sciences, Nitte University, Mangalore, India.
J Cosmet Dermatol. 2018 Dec;17(6):1073-1083. doi: 10.1111/jocd.12470. Epub 2017 Dec 10.
Most of the sunscreen formulations mainly contain chemicals or synthetic molecules. Nowadays, researchers are mainly focussing on herbal formulations due to toxicity of the synthetic molecules. Silymarin is a natural flavonoids having excellent antioxidant properties. Solid lipid nanoparticles are novel drug carriers which improve the drug stability and tolerance effect and also enhance the permeation effect.
This study aimed at the preparation of solid lipid nanoparticles containing silymarin that will be incorporated into a sunscreen cream and determine its sun protection factor.
The solid lipid nanoparticles were prepared by micro-emulsion method; here, the glyceryl monostearate was used as lipid, and Tween 80 was used as an emulsifier. The solid lipid nanoparticles were evaluated for drug entrapment, particle size and morphology, zeta potential, and polydispersity index. The dispersion was formulated into sunscreen cream and evaluated for various parameters, such as extrudability, viscosity, spreadability, drug content, in vitro drug release, ex vivo permeation of drug, in vitro and in vivo sun protection factor determination, in vivo skin irritation test, and accelerated stability studies.
The results suggested that as the concentration of emulsifier increased, the entrapment efficiency of silymarin increased. In vitro and in vivo sun protection factor determination showed that SPF of 13.80 and 14.1, respectively. Stability studies were performed under accelerated conditions, and it did not show any appreciable change in parameters.
These results indicated that the sunscreen containing silymarin solid lipid nanoparticles exhibited better photoprotective action.
大多数防晒配方主要含有化学物质或合成分子。如今，由于合成分子的毒性，研究人员主要关注草药配方。水飞蓟素是一种具有优异抗氧化性能的天然黄酮类化合物。固体脂质纳米粒是新型药物载体，可提高药物稳定性和耐受效果，还能增强渗透效果。
本研究旨在制备含有水飞蓟素的固体脂质纳米粒，并将其掺入防晒霜中，测定其防晒系数。
采用微乳法制备固体脂质纳米粒；在此，单硬脂酸甘油酯用作脂质，吐温80用作乳化剂。对固体脂质纳米粒进行药物包封率、粒径和形态、zeta电位及多分散指数评估。将该分散体制成防晒霜，并对其各种参数进行评估，如挤出性、粘度、铺展性、药物含量、体外药物释放、药物的离体渗透、体外和体内防晒系数测定、体内皮肤刺激性试验以及加速稳定性研究。
结果表明，随着乳化剂浓度的增加，水飞蓟素的包封效率提高。体外和体内防晒系数测定显示，防晒系数分别为13.80和14.1。在加速条件下进行稳定性研究，各项参数未显示出任何明显变化。
这些结果表明，含有水飞蓟素固体脂质纳米粒的防晒霜具有更好的光保护作用。
