title: Incorporation of quercetin in lipid microparticles: effect on photo- and chemical-stability.
abstract: 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.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Ferrara, via Fossato di Mortara 17, 44100 Ferrara, Italy. sls@unife.it
authors.forename: Santo
authors.initials: S
authors.lastname: Scalia
authors.forename: Matteo
authors.initials: M
authors.lastname: Mezzena
mesh_terms: D002853:Chromatography, Liquid; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions; D008027:Light; D008055:Lipids / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010713:Phosphatidylcholines / Q000737:chemistry; D010782:Photolysis; D011208:Powders; D011794:Quercetin / Q000737:chemistry* / Q000528:radiation effects; D015203:Reproducibility of Results; D014280:Triglycerides / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D003692:Delayed-Action Preparations; D004655:Emulsions; D008055:Lipids; D010713:Phosphatidylcholines; D011208:Powders; D014280:Triglycerides; D011794:Quercetin; C022618:tristearin