CONICET | Buscador de Institutos y Recursos Humanos

Layered Double Hydroxides or anionic clays are biocompatible compounds with application in the pharmaceutical fields. Particularly, much attention has been focused on the use of layered double hydroxides as support for controlled release systems of drugs, vitamins, biomolecules, etc. Layered double hydroxides or anionic clays are composed by positively charged hydroxides sheets, of few nanometers and interlayer exchangeable anions. The anions insertion in the interlayer zone is carried out by two routes, coprecipitation (direct method) and anion exchange (indirect method). With indirect route was prepared first host laminar solid by coprecipitation and then the desired anion introduced by the contact of a given time with stirring and the temperature. Sodium diclofenac is a non-steroidal antiimflamatory drug used for the relief of symptoms of osteoarthritis and rheumatoid arthritis. In the present work studied sodium diclofenac intercalated into nanoclays layered double hydroxides as previously mentioned. The host laminar solid and direct method was prepared by coprecipitation of Aluminum-Magnesium salts at pH 10±0.2; on N2 atmosphere. By X-ray diffraction was observed the drug incorporation into nanoclay. The basal spacing obtained suggests that the drugs molecules are arranged in partially interdigitated bilayers. The amount of intercalated sodium diclofenac was determined by UV-visible spectroscopy. By the direct method greater incorporation was obtained.Differential scanning calorimetry thermogram of sodium diclofenac shows two endothermic peaks at 270°C and 350°C due to the melting point and the oxidative of degradation. Differential scanning calorimetry of sodium diclofenac incorporated into layered double hydroxides present an exothermic peak at 255°C probably corresponding to oxidative degradation of the superficial drug. At higher temperatures (410°C) the decomposition of the drug and destruction of the layers of the layered double hydroxides isobserved. This behavior indicated a thermal stabilization of the drug.