Chitin or chitin derivative microcapsules containing a hydrophobic substance, particularly a sun filter and method for preparing such microcapsules

摘要

Microcapsules involving a wall of chitin or chitin derivatives or of polyhydroxylated polyamines or one of their salts, with the wall sheathing a hydrophobic substance, are prepared by forming a hydrophobic phase emulsion of the hydrophobic substance in an aqueous phase containing an anionic surfactant capable of causing insolubilization of chitosan or chitosan derivatives or polyhydroxylated polyamines, mixing the emulsion with a chitosan or chitosan derivative or polyhydroxylated polyamine organic salt so as to cause the coacervation of the chitosan or the chitosan derivatives or the polyhydroxylated polyamines around the droplets of the hydrophobic phase, subjecting the chitosan or chitosan derivative or the polyhydroxylated polyamine coacervate to an acetylation or crosslinking reaction and recovering the microcapsules, and are applicable to cosmetic compositions incorporating sunscreens.