This invention relates to a method for forming hollow silica-based particles suitable for containing one or more active ingredients or for containing other smaller particles which may include one or more active ingredients. In the method, an emulsion is prepared including a continuous phase that is polar or non-polar, and a dispersed phase comprising droplets including (i) a polar active ingredient when the continuous phase is non-polar or (ii) a non-polar active ingredient when the continuous phase is polar; and a prehydrolyzed silica precursor is added to the emulsion such that the silica precursor can be emulsion templated on the droplets to form hollow silica-based particles.