Sanad R A, Abdel Malak N S, El-Bayoomy T S, Badawi A A
Department of Pharmaceutics, Faculty of Pharmacy Cairo University, Cairo, Egypt.
Drug Discov Ther. 2010 Dec;4(6):472-83.
The objective of the current study was to formulate solid lipid nanoparticles of oxybenzone to enhance its sunscreening efficacy while reducing its side effects. Solid lipid nanoparticles (SLNs) of oxybenzone were prepared by the solvent diffusion method. A complete 2(4) factorial design was used to optimize preparations. The study design involves the investigation of four independent variables, namely lipid type (Glyceryl monostearate, GMS; and Witepsol E85, WE85), lipid concentration (5 and 10%), polyvinyl alcohol (PVA) concentration (1 and 2%), and ethanol/acetone ratios (1:1 and 3:1, v/v), in terms of their effect on the particle size and entrapment efficiency. GMS was found to significantly increase the p.s. and EE%. SLNs prepared using 10% lipid had slower drug release compared to those prepared using 5%. The candidate oxybenzone-loaded SLN formula (SLN2) consisting of 0.5% oxybenzone, 10% GMS, 1% PVA, and ethanol/acetone (1:1, v/v) was then formulated into a gel and compared to the corresponding free oxybenzone nanosuspension and placebo SLN. The formulations were evaluated for skin irritation, in vitro sun protection factor, and ultraviolet A protection factors. The incorporation of oxybenzone into solid lipid nanoparticles greatly increased the SPF and UVA protection factor of oxybenzone more than five-fold while providing the advantage of overcoming skin irritancy problems.
本研究的目的是制备二苯甲酰甲烷固体脂质纳米粒，以提高其防晒效果并减少副作用。采用溶剂扩散法制备了二苯甲酰甲烷固体脂质纳米粒（SLNs）。采用完全2(4)析因设计对制剂进行优化。该研究设计涉及考察四个自变量，即脂质类型（单硬脂酸甘油酯，GMS；和Witepsol E85，WE85）、脂质浓度（5%和10%）、聚乙烯醇（PVA）浓度（1%和2%）以及乙醇/丙酮比例（1:1和3:1，v/v）对粒径和包封率的影响。发现GMS能显著增加粒径和包封率。与使用5%脂质制备的SLNs相比，使用10%脂质制备的SLNs药物释放较慢。然后将由0.5%二苯甲酰甲烷、10% GMS、1% PVA和乙醇/丙酮（1:1，v/v）组成的载二苯甲酰甲烷的候选SLN配方（SLN2）制成凝胶，并与相应的游离二苯甲酰甲烷纳米混悬液和安慰剂SLN进行比较。对这些制剂进行了皮肤刺激性、体外防晒系数和紫外线A防护系数的评估。将二苯甲酰甲烷掺入固体脂质纳米粒中，可使二苯甲酰甲烷的防晒系数和紫外线A防护系数大幅提高五倍以上，同时具有克服皮肤刺激性问题的优势。
