Capsule comprising active ingredient

A method for producing capsules with a core/shell structure, comprising in each case

• a core which comprises at least one sparingly water-soluble or water-insoluble organic active ingredient selected from an organic UV filter, and
• a shell which directly surrounds the core, where the shell comprises nanoparticles of a metal oxide or semimetal oxide and these nanoparticles are joined together by at least one further metal oxide or semimetal oxide, where the further metal oxide or semimetal oxide joining the nanoparticles has been formed by hydrolysis and subsequent polycondensation of a water-insoluble or sparingly water-soluble sol-gel precursor, comprising the steps
• i) preparation of an oil-in-water emulsion by emulsifying an oil phase which comprises at least one water-insoluble or sparingly water-soluble sol-gel precursor and at least one sparingly water-soluble or water-insoluble organic active ingredient in a water phase which comprises nanoparticles of a metal oxide or semimetal oxide, using shear forces,
• ii) establishment of a pH in the aqueous phase of the emulsion at a value at which the hydrolysis and the subsequent polycondensation of the water-insoluble or sparingly water-soluble sol-gel precursor to form the shell surrounding the core takes place, and
• iii) optionally, purification and/or isolation of the capsules with core/shell structure produced in step ii),
• where the capsule comprises no organic surfactants.