Intercalation of mefenamic and meclofenamic acid anions in hydrotalcite-like matrixes

Layered double hydroxides with Mg and Al cations in the layers (Mg/Al molar ratio 2) and with intercalated mefenamic and meclofenamic acid anions have been prepared by coprecipitation, ion exchange and reconstruction. The solids have been characterized by X-ray diffraction, FTIR spectroscopy and assessment of specific surface area; their thermal stability has been studied by differential thermal and thermogravimetric analyses. Intercalation has been achieved by all three methods used, the gallery height ranging between 16.5 and 17.5 A, depending on the particular drying conditions, these values suggesting the organic molecules form bilayers in the interlayer space.