In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax–decyl oleate nanoparticles

• Published in: European journal of pharmaceutics and biopharmaceutics 2007, Vol.65 (1), p.122-125
• Main Authors: Villalobos-Hernández, J.R., Müller-Goymann, C.C.
• Format: Article
• Language: English
• Subjects: Barium Sulfate - chemistry; Biological and medical sciences; Carbonates - chemistry; Chemistry, Pharmaceutical; Colloids; Diseases of the skin. Cosmetics; Drug Carriers; Drug Compounding; Erythema - etiology; Erythema - prevention & control; General pharmacology; In vitro erythemal UVA protection factor; Inorganic sunscreens; Medical sciences; Nanoparticles; Nanostructured lipid carriers (NLC); Oleic Acids - chemistry; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Strontium - chemistry; Sunscreening Agents - chemistry; Sunscreening Agents - pharmacology; Titanium - chemistry; Ultraviolet Rays - adverse effects; Waxes - chemistry
• ISSN: 0939-6411; 1873-3441
• DOI: 10.1016/j.ejpb.2006.07.013

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.