In latest years, many natural and synthetic solid carriers attract increasing attention, due to theirs biocompatibility, acceptable ecological and toxicological properties, possible modification of physico-chemical properties, simple production, high stability and relatively low price. These carriers have similar chemical structure, mostly based on silicon-dioxide, magnesium aluminometasilicate and calcium phosphate, and differ from each other in structure porosity, specific surface area, size, volume and shape of pores, and possibility of surface functionalization. Ordered mesoporous materials like MCM - 41 and SBA - 15, as well as porous materials from Neusilin® and Sylysia® groups, represent the most common adsorbents evaluated in order to increase drug dissolution rate, and its bioavailability, and also in modifiedand targeted drug release formulations. Also, natural silica material, isolated from diatomites, diatom microshells, with its unique characteristics, represents relatively cheap solid carrier used in formulation of oral dosage forms and implants. Modern adsorbents are mostly used in formulations of solid dispersions with low water-soluble drugs, or as solid carriers for lipid formulations. In latest years, modern porous carriers are evaluated for possible surface functionalization in order to achieve prolonged or signal-initiated drug release.