Department of Pharmaceutical Sciences, University of Bologna, via S. Donato 19, Bologna, Italy.
J Pharm Sci. 2009 Aug;98(8):2759-69. doi: 10.1002/jps.21636.
Solid lipid microparticles (SLMs) loaded with high amounts of the sunscreen agent, butyl methoxydibenzoylmethane (avobenzone) were prepared in order to reduce its photoinstability. The microparticles were produced, using carnauba wax as lipidic material and phosphatidylcholine as the surfactant, by the classical melt dispersion method or the spray congealing technique with pneumatic atomizer. The sunscreen agent loading was 40.1-48.5% (w/w), with no significant differences between the production methods. However, release studies indicated that spray congealing enabled a more efficient modulation of avobenzone release from the SLMs (26% of encapsulated avobenzone released after 2 h as compared to 60% for melt dispersion). The photoprotective efficacy of the SLMs was evaluated after their introduction in a model cream. A statistically significant decrease of the light-induced degradation of avobenzone was obtained by the SLMs prepared by the melt dispersion procedure (the extent of degradation was 38.6 +/- 3.6% for nonencapsulated avobenzone and 32.1 +/- 4.3% for the microparticle-entrapped sunscreen). On the other hand, the SLMs produced by spray congealing achieved a more marked reduction in avobenzone photodecomposition to 15.4 +/- 4.1%. Therefore, the spray congealing technique was superior to the classical melt dispersion method for rapid and solvent free production of SLMs with a high avobenzone loading capacity.
为了降低防晒剂丁基甲氧基二苯甲酰基甲烷（阿伏苯宗）的光不稳定性，制备了负载大量该防晒剂的固体脂质微球（SLMs）。采用巴西棕榈蜡作为脂质材料，磷脂酰胆碱作为表面活性剂，通过经典的熔融分散法或气动雾化器的喷雾凝固技术制备微球。防晒剂的载药量为 40.1-48.5%（w/w），两种生产方法之间没有显著差异。然而，释放研究表明，喷雾凝固技术能够更有效地调节 SLMs 中阿伏苯宗的释放（2 小时后释放的包封阿伏苯宗为 26%，而熔融分散法为 60%）。将 SLMs 引入模型乳膏中后，评估了其光保护功效。通过熔融分散法制备的 SLMs 显著降低了光诱导的阿伏苯宗降解（未包封的阿伏苯宗的降解程度为 38.6 +/- 3.6%，而微球包封的防晒剂为 32.1 +/- 4.3%）。另一方面，喷雾凝固法制备的 SLMs 使阿伏苯宗光分解的减少更为显著，达到 15.4 +/- 4.1%。因此，喷雾凝固技术优于经典的熔融分散法，可快速、无溶剂地生产具有高阿伏苯宗载药量的 SLMs。
