title: A new approach for increasing ascorbyl palmitate stability by addition of non-irritant co-antioxidant.
abstract: The aim of this work was to test innovative approach for enhancing ascorbyl palmitate stability in microemulsions for topical application by addition of newly synthesized co-antioxidant 4-(tridecyloxy)benzaldehyde oxime (TDBO) and to investigate its antioxidant activity and finally to evaluate cytotoxicity of TDBO-loaded microemulsions on keratinocyte cells. TDBO significantly increased ascorbyl palmitate stability in oil-dispersed-in-water (o/w) microemulsions, most presumably due to reduction of ascorbyl palmitate radical back to ascorbyl palmitate, since TDBO free-radical scavenging activity was confirmed. Cytotoxicity experiments demonstrated no significant change in cell viability or morphology in the presence of TDBO-loaded microemulsions regarding unloaded microemulsions, although greater cytotoxicity was observed with increased microemulsion concentrations. Therefore, the incorporation of TDBO as non-cytotoxic co-antioxidant in o/w microemulsions is a promising new strategy for enhancing ascorbyl palmitate stability that could be used to support antioxidant network in the skin.
authors.affiliation: Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Gosenca
authors.forename: Aleš
authors.initials: A
authors.lastname: Obreza
authors.forename: Slavko
authors.initials: S
authors.lastname: Pečar
authors.forename: Mirjana
authors.initials: M
authors.lastname: Gašperlin
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D004655:Emulsions / Q000138:chemical synthesis* / Q000494:pharmacology*; D006801:Humans; D007509:Irritants; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D004655:Emulsions; D007509:Irritants; D001205:Ascorbic Acid; C031226:6-O-palmitoylascorbic acid