title: A novel approach based on lipid nanoparticles (SLN) for topical delivery of alpha-lipoic acid.
abstract: This study describes the development, preparation and characterization of solid lipid nanoparticles (SLN) containing the novel anti-ageing substance alpha-lipoic acid. Lipoic acid is chemically labile, i.e. the degradation products possess an unpleasant odour. Therefore, the active was encapsulated in SLN. A lipid with low melting point (Softisan 601) was selected for preparation of active-loaded SLN after screening the solubility of alpha-lipoic acid in physicochemically different lipids. An entrapment efficiency of 90% (UV analysis) was obtained for all developed formulations using Miranol Ultra C32 as emulsifying agent. Particle size stability was monitored during 3 months storing the samples at 20 degrees C and at 4 degrees C. Results of DSC analysis confirm that these systems are characterized by a solid-like behaviour, although with a very low crystallinity index.
authors.affiliation: Department of Pharmaceutical Technology, Biotechnology and Quality Management, The Free University of Berlin, Berlin, Germany.
authors.forename: E B
authors.initials: EB
authors.lastname: Souto
authors.forename: R H
authors.initials: RH
authors.lastname: Müller
authors.forename: S
authors.initials: S
authors.lastname: Gohla
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D003358:Cosmetics / Q000008:administration & dosage; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D004355:Drug Stability; D006801:Humans; D008055:Lipids / Q000737:chemistry; D049329:Nanostructures; D010316:Particle Size; D012212:Rheology; D013696:Temperature; D008063:Thioctic Acid / Q000008:administration & dosage*; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D003358:Cosmetics; D004337:Drug Carriers; D008055:Lipids; D008063:Thioctic Acid