Layered double hydroxides (LDHs) with the hydrotalcite type structure and a Mg:Al ratio of two have been prepared, with salicylate or naproxen in the interlayer. Two synthetic routes have been used: reconstruction from a mildly calcined hydrotalcite-CO 3 precursor, and a coprecipitation method with chlorides of the metals. The solids have been characterized using several physicochemical techniques, i.e., powder X-ray diffraction, FTIR and 13 C CP/MAS NMR spectroscopies and thermal analysis (thermogravimetric and differential thermal analyses). The gallery height determined is in all cases larger than the size of the drug, 11.5Å for salicylate and 15.8 and 16.6Å for naproxen, depending on the specific synthesis route followed. Experimental data suggest the anion molecules form a tilted bilayer, with the carboxylate groups pointing towards the brucite-like layers. The solids are stable up to 230°C and their evolution from 350°C upwards is very similar to that observed for a carbonate-containing hydrotalcite, forming mostly amorphous solids with a large specific surface area.