Porous apatite particles with an average diameter of 3-4 mum were produced by spray drying a suspension of apatite nanoparticles, which were previously obtained by precipitation in a calcium/citrate/phosphate solution. The high surface area of the porous particles indicates a highly porous structure. The so produced spray dried apatite particles have the capability to adsorb and release a model drug compound (salicylic acid) in solutions at physiological pH.