Scalia Santo, Mezzena Matteo
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, via Fossato di Mortara 17, 44100 Ferrara, Italy.
J Pharm Biomed Anal. 2009 Jan 15;49(1):90-4. doi: 10.1016/j.jpba.2008.10.011. Epub 2008 Oct 22.
Lipid microparticles loaded with the flavonoid, quercetin were developed in order to enhance its stability in topical formulations. The microparticles were produced using tristearin as the lipid material and phosphatidylcholine as the emulsifier. The obtained lipoparticles were characterized by release studies, scanning electron microscopy and powder X-ray diffractometry. The quercetin loading was 12.1% (w/w). Free or microencapsulated quercetin was introduced in a model cream formulation (oil-in-water emulsion) and irradiated with a solar simulator. The extent of photodegradation was measured by high-performance liquid chromatography. The light-induced decomposition of quercetin in the cream vehicle was markedly decreased by incorporation into the lipid microparticles (the extent of degradation was 23.1+/-3.6% for non-encapsulated quercetin compared to 11.9+/-2.5% for the quercetin-loaded microparticles) and this photostabilization effect was maintained over time. Moreover, the chemical instability of quercetin, during 3-month storage of the formulations at room temperature and in the dark, was almost completely suppressed by the lipid microparticle system. Therefore incorporation of quercetin in lipoparticles represents an effective strategy to enhance its stability in dermatological products.
为提高黄酮类化合物槲皮素在局部制剂中的稳定性，制备了负载槲皮素的脂质微粒。以三硬脂酸甘油酯为脂质材料、磷脂酰胆碱为乳化剂制备微粒。通过释放研究、扫描电子显微镜和粉末X射线衍射对所得脂质体进行表征。槲皮素载量为12.1%（w/w）。将游离或微囊化的槲皮素引入模型乳膏制剂（水包油乳液）中，并用太阳模拟器照射。通过高效液相色谱法测定光降解程度。通过将槲皮素掺入脂质微粒中，乳膏载体中槲皮素的光诱导分解明显减少（未包封的槲皮素降解程度为23.1±3.6%，而载槲皮素微粒为11.9±2.5%），并且这种光稳定作用随时间保持。此外，在制剂于室温黑暗条件下储存3个月期间，槲皮素的化学不稳定性几乎被脂质微粒系统完全抑制。因此，将槲皮素掺入脂质体是提高其在皮肤科产品中稳定性的有效策略。
