Immobilization of Ibuprofen and Copper-Ibuprofen Drugs on Layered Double Hydroxides

The immobilization of the NSAID ibuprofen (Hibp) and the Cu(II)-ibp compound on magnesium-aluminum layered double hydroxides (Mg3Al-LDH) is described. Ibuprofen was intercalated on LDHs by three routes (ion exchange, co-precipitation, and reconstruction). The organic drug and the Cu(II)-ibp were also immobilized by adsorption on LDH external surfaces. Materials were characterized by elemental analysis, UV/VIS, FTIR, and Raman spectroscopies, powder X-ray diffractometry (XRD), thermogravimetry, and electronic paramagnetic resonance (EPR). Mg3Al-(ibp)cop (30% w/w of drug/material) and Mg3Al-(ibp)ie (33%) materials exhibit bilayer arrangements of ibp anions intercalated between the host layers. Mg3Al-(ibp)rec and Mg3Al-(ibp)ads contain 13% and 6.2% of ibuprofenate, respectively. Mg3Al-(Cu-ibp)ads exhibits two Cu centers in different environments interacting with host layers. Pharmacological potential of materials are compared considering the amounts of immobilized drugs and their buffering properties. Mg3Al-(ibp)ie and Mg3Al-(ibp)cop exhibit poor buffering property, but contain high ibp amounts. Mg3Al-(ibp)ads despite having buffering property, contains low amount of ibuprofen. Mg3Al-(ibp)rec combines significant amount of immobilized ibp with good buffering property. Mg3Al-(Cu-ibp)ads, due to the buffering property, may be an interesting new formulation aiming to decrease gastric irritation. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association