Tursilli Rosanna, Piel Géraldine, Delattre Luc, Scalia Santo
Department of Pharmaceutical Sciences, University of Ferrara, Italy.
Eur J Pharm Biopharm. 2007 Jun;66(3):483-7. doi: 10.1016/j.ejpb.2007.02.017. Epub 2007 Feb 28.
Solid lipid microparticles (SLMs) loaded with the sunscreen agent, octyl-dimethylaminobenzoate (ODAB), were prepared in order to achieve enhanced sunscreen photostability. The microparticles were produced by the melt dispersion technique using glyceryl behenate as lipidic material and poloxamer 188 as the emulsifier. The obtained SLMs showed proper features in terms of morphology, size distribution (1.67-15.81 microm) and ODAB loading (16.15+/-0.11%, w/w). The sunscreen release from the SLMs was slower than its dissolution rate and the photodecomposition of ODAB was markedly decreased (>51.3%) by encapsulation into the lipid microparticles. The efficacy of the SLM carrier system was also evaluated after their introduction in model topical formulations (i.e., hydrogel and oil-in-water emulsion). Further in vitro release measurements, performed using Franz diffusion cells with polycarbonate membranes, indicated that the retention capacity of the microparticles was lost after their incorporation into the emulsion, whereas it was retained in the hydrogel. Moreover, the SLMs achieved a reduction of the sunscreen photodegradation in the hydrogel vehicle (the ODAB loss decreased from 87.4% to 59.1%), whereas no significant photoprotective effect was observed in the emulsion. Therefore, the efficacy of the ODAB-loaded SLMs was markedly affected by the vehicle.
为提高防晒剂辛基二甲基氨基苯甲酸酯（ODAB）的光稳定性，制备了负载该防晒剂的固体脂质微粒（SLMs）。采用熔融分散技术，以山嵛酸甘油酯为脂质材料、泊洛沙姆188为乳化剂制备微粒。所得SLMs在形态、粒径分布（1.67 - 15.81微米）和ODAB负载量（16.15±0.11%，w/w）方面表现出合适的特性。SLMs中防晒剂的释放比其溶解速率慢，并且通过包封到脂质微粒中，ODAB的光分解显著降低（>51.3%）。在将SLM载体系统引入模型外用制剂（即水凝胶和水包油乳液）后，也对其功效进行了评估。使用带有聚碳酸酯膜的Franz扩散池进行的进一步体外释放测量表明，微粒掺入乳液后其保留能力丧失，而在水凝胶中则得以保留。此外，SLMs在水凝胶载体中实现了防晒剂光降解的降低（ODAB损失从87.4%降至59.1%），而在乳液中未观察到显著的光保护作用。因此，负载ODAB的SLMs的功效受到载体的显著影响。
