title: In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.
abstract: This paper describes the in vitro photoprotection in the UV-A range, i.e. 320-400 nm obtained by the use of carnauba wax-decyl oleate nanoparticles either as encapsulation systems or as accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate and titanium dioxide. Lipid-free inorganic sunscreen nanosuspensions, inorganic sunscreen-free wax-oil nanoparticle suspensions and wax-oil nanoparticle suspensions containing inorganic sunscreens dispersed either in their oil phase or their aqueous phase were prepared by high pressure homogenization. The in vitro erythemal UV-A protection factors (EUV-A PFs) of the nanosuspensions were calculated by means of a sun protection analyzer. EUV-A PFs being no higher than 4 were obtained by the encapsulation of barium sulfate and strontium carbonate, meanwhile by the distribution of titanium dioxide in presence of wax-oil nanoparticles, the EUV-A PFs varied between 2 and 19. The increase in the EUV-A PFs of the titanium dioxide obtained by the use of wax-oil nanoparticles demonstrated a better performance of the sun protection properties of this pigment in the UV-A region.
authors.affiliation: Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany.
authors.forename: J R
authors.initials: JR
authors.lastname: Villalobos-Hernández
authors.forename: C C
authors.initials: CC
authors.lastname: Müller-Goymann
mesh_terms: D001466:Barium Sulfate / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003102:Colloids; D004337:Drug Carriers; D004339:Drug Compounding; D004890:Erythema / Q000209:etiology / Q000517:prevention & control; D053758:Nanoparticles; D009829:Oleic Acids / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry; D013473:Sunscreening Agents / Q000737:chemistry* / Q000494:pharmacology; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays / Q000009:adverse effects; D014885:Waxes / Q000737:chemistry*
chemical_list: D002254:Carbonates; D003102:Colloids; D004337:Drug Carriers; D009829:Oleic Acids; D013473:Sunscreening Agents; D014885:Waxes; C009495:titanium dioxide; D001466:Barium Sulfate; C054286:strontium carbonate; D014025:Titanium; C026344:carnauba wax; D013324:Strontium