title: Lecithin based lamellar liquid crystals as a physiologically acceptable dermal delivery system for ascorbyl palmitate.
abstract: Liquid crystalline systems with a lamellar structure have been extensively studied as dermal delivery systems. Ascorbyl palmitate (AP) is one of the most studied and used ascorbic acid derivatives and is employed as an antioxidant to prevent skin aging. The aim of this study was to develop and characterize skin-compliant dermal delivery systems with a liquid crystalline structure for AP. First, a pseudoternary phase diagram was constructed using Tween 80/lecithin/isopropyl myristate/water at a Tween 80/lecithin mass ratio of 1/1, and the region of lamellar liquid crystals was identified. Second, selected unloaded and AP-loaded lamellar liquid crystal systems were physicochemically characterized with polarizing optical microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheology techniques. The interlayer spacing and rheological parameters differ regarding quantitative composition, whereas the microstructure of the lamellar phase was affected by the AP incorporation, resulting either in additional micellar structures (at 25 and 32 °C) or being completely destroyed at higher temperature (37°C). After this, the study was oriented towards in vitro cytotoxicity evaluation of lamellar liquid crystal systems on a keratinocyte cell line. The results suggest that the lamellar liquid crystals that were developed could be used as a physiologically acceptable dermal delivery system.
authors: University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia.
authors: Mirjam
authors: M
authors: Gosenca
authors: Marija
authors: M
authors: Bešter-Rogač
authors: Mirjana
authors: M
authors: Gašperlin
mesh_terms: D000279:Administration, Cutaneous; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives*; D002152:Calorimetry, Differential Scanning; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects; D054709:Lecithins / Q000737:chemistry* / Q000633:toxicity; D050866:Liquid Crystals / Q000737:chemistry* / Q000633:toxicity; D008859:Microscopy, Polarization; D044367:Phase Transition; D053838:Scattering, Small Angle; D015595:Skin Aging / Q000187:drug effects; D014783:Viscosity; D014961:X-Ray Diffraction
chemical_list: D000975:Antioxidants; D004337:Drug Carriers; D054709:Lecithins; D001205:Ascorbic Acid; C031226:6-O-palmitoylascorbic acid
keywords: Ascorbyl palmitate; Cytotoxicity; Keratinocytes; Lamellar liquid crystalline phase; Pseudoternary phase diagram