NANOHIBRIDS OF LDH-AINES DRUGS: SYNTHESIS, CHARACTERIZACION AND STABILITY PROPERTIES

SILVIA MENDIETA; MARCOS OLIVA; CELSO F. PÉREZ; EDUARDO HERRERO; ANGELICA HEREDIA; MÓNICA CRIVELLO

Conferencia; 5th Czech-Italian-Spanish Conference on Molecular Sieves and Catalysis; 2013

Layered double hydroxides (LDH), also known as hydrotalcite like compounds or anionicclay, have technological importance in catalysis, optics, medical science andnanocomposite material engineering. Moreover, LDH are biocompatible materials, andmay act as stable host matrices for storage and delivery of various intercalated bioactivemolecules and drugs. One important feature is that the labile bioactive substancesintercalated into LDH could effectively be protected against rapid degradation by light,temperature, oxygen, alkali metals, etc.Indomethacin is a member of the NSAID. It is used to reduce pain involved inosteoarthritis, rheumatoid arthritis, bursitis, gout, etc., however, are well known sideeffects including gastrointestinal disturbance. The drug is described as poorly soluble andhighly permeable (class II) drug.The MgAl-Indo samples have been prepared following direct synthesis by coprecipitationfrom Mg and Al chlorides; was added over a suspension with indomethacin.The synthesis was prepared at different pH (8, 9 and 10) +/- 0.2; the pH was maintainedconstant by continuous adding of 0.1 M NaOH. The coprecipitation was carried out at 35 ºC under nitrogen atmosphere to avoid the incorporation of CO2. The resulting suspensionwas stirred for 20 h at 60 ºC under nitrogen atmosphere.The samples were characterized by X-ray powder diffraction, FT-IR spectra, Scanningelectron microscopy, Thermogravimetric analyses and Differential scanning calorimetryanalyses. Drug content was determined by UV absorption spectrophotometer Jasco 7800 at 320 nm.Successful intercalation of indomethacin into the LDH host is demonstrated by the XRDdiagrams of the nano hybrids. On the other hand, the drug was absorbed on the surface ofthe LDH synthesized at pH 8 and 9. At pH = 10 showed higher order crystalline structureof LDH. The drug suffers a change of structure due to the heat treatments performedduring the synthesis confirmed by FT-IR. The nanoclay confers more thermal stability tothe drug observed by DSC; the decomposition temperature is enhanced about 100 ºC. Themaximum incorporation was obtained with LDH synthesized at pH=8. The present resultsimply that the nano hybrids particles can be potentially used as a novel drug storage anddelivery.