Process for producing composite materials by reactive spray-drying, where a liquid phase A, which comprises inorganic cations, and a liquid phase B, which comprises anions which, with the inorganic cations, form a salt that is insoluble in the mixture of the liquid phases are sprayed together using at least one multi-substance nozzle, and where at least one hydrophobic active ingredient is present in dissolved form in at least one liquid spraying phase, and where the salt formed from the cations of phase A and the anions of phase B has a solubility of less than 0.02 mol/l in the neutral aqueous medium.