title: Evaluation of nanostructured lipid carriers (NLC) and nanoemulsions as carriers for UV-filters: characterization, in vitro penetration and photostability studies.
abstract: The increased awareness of protection against UV radiation damages has led to a rise in the use of topically applied chemical sunscreen agents and to an increased need of innovative carriers designed to achieve the highest protective effect and reduce the toxicological risk resulting from the percutaneous absorption of these substances. In this paper, nanostructured lipid carriers (NLC) and nanoemulsions (NE) were formulated to optimize the topical application of different and widespread UVA or UVB sun filters (ethyl hexyltriazone (EHT), diethylamino hydroxybenzoyl hexyl benzoate (DHHB), bemotrizinol (Tinosorb S), octylmethoxycinnamate (OMC) and avobenzone (AVO)). The preparation and stability parameters of these nanocarriers have been investigated concerning particle size and zeta potential. The release pattern of the sunscreens from NLC and NE was evaluated in vitro, determining their percutaneous absorption through excised human skin. Additional in vitro studies were performed in order to evaluate, after UVA radiation treatment, the spectral stability of the sunfilters once formulated in NLC or NE. From the results obtained, when incorporated in NLC, the skin permeation abilities of the sun filter were drastically reduced, remaining mainly on the surface of the skin. The photostability studies showed that EHT, DHHB and Tinosorb S still retain their photostability when incorporated in these carriers, while OMC and AVO were not photostable as expected. However, no significant differences in terms of photoprotective efficacy between the two carriers were observed.
authors.affiliation: Dipartimento di Scienze del Farmaco, Università di Catania, 95125 Catania, Italy. Electronic address: capuglia@unict.it.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Puglia
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Damiani
authors.forename: Alessia
authors.initials: A
authors.lastname: Offerta
authors.forename: Luisa
authors.initials: L
authors.lastname: Rizza
authors.forename: Giorgia Giusy
authors.initials: GG
authors.lastname: Tirendi
authors.forename: Maria Stella
authors.initials: MS
authors.lastname: Tarico
authors.forename: Sergio
authors.initials: S
authors.lastname: Curreri
authors.forename: Francesco
authors.initials: F
authors.lastname: Bonina
authors.forename: Rosario Emanuele
authors.initials: RE
authors.lastname: Perrotta
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D004337:Drug Carriers / Q000737:chemistry*; D004355:Drug Stability; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D010539:Permeability; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption / Q000502:physiology; D013473:Sunscreening Agents / Q000737:chemistry* / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D004337:Drug Carriers; D008055:Lipids; D013473:Sunscreening Agents
keywords: Human skin; In vitro percutaneous absorption; Nanostructured lipid carriers; Photo-stability studies; Sun filters