Skin penetration and photoprotection of topical formulations containing benzophenone-3 solid lipid microparticles prepared by the solvent-free spray-congealing technique.
OBJECTIVE
Solid-lipid microparticles loaded with high amounts of the sunscreen UV filter benzophenone-3 were prepared by spray congealing with the objective of decreasing its skin penetration and evaluate whether the sunscreen's photoprotection were impaired by the microencapsulation process.


METHODS
The microparticles were produced using the natural lipids carnauba wax or bees wax and three different concentrations of benzophenone-3 (30, 50 and 70%) using spray congealing technique.


RESULTS
The microparticles presented properties suitable for topical application, such as spherical morphology, high encapsulation efficiency (95.53-102.2%), average particle sizes between 28.5 and 60.0 µm with polydispersivities from 1.2 to 2.5. In studies of in vitro skin penetration and preliminary stability, formulations of gel cream containing carnauba wax solid lipid microparticles and 70% benzophenone-3 when compared to the formulation added of bees wax solid-lipid microparticles containing 70% benzophenone-3, was stable considering the several parameters evaluated and were able to decrease the penetration of the UV filter into pig skin. Moreover, the formulations containing solid lipid microparticles with 70% benzophenone-3 increased the photoprotective capacity of benzophenone-3 under UV irradiation.


CONCLUSIONS
The results show that spray-congealed microparticles are interesting solid forms to decrease the penetration solar filters in the skin without compromising their photoprotection.
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto , Brazil.
Rodrigo Molina
RM
Martins
Silvia
S
Siqueira
Maria José Vieira
MJ
Fonseca
Luis Alexandre Pedro
LA
Freitas
D000818:Animals; D001577:Benzophenones / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D002214:Capsules; D002460:Cell Line; D008055:Lipids / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D051379:Mice; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D013473:Sunscreening Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D013552:Swine; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014885:Waxes / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
D001577:Benzophenones; D002214:Capsules; D008055:Lipids; D013473:Sunscreening Agents; D014885:Waxes; C005290:oxybenzone; C026344:carnauba wax
Chemical stability; microparticles; natural lipids; pig skin; sunscreen