Nanoclays Aluminum-Magnesium: Influence on the Thermal Stability of Sodium Diclofenac

SILVIA MENDIETA; CELSO PÉREZ; MAIA LUDUEÑA; MÓNICA CRIVELLO

Córdoba

Congreso; 3ª Reunión Internacional de Ciencias Farmacéuticas (RICiFA); 2014

RICIFA

Layered Double Hydroxides or anionic clays is a biocompatible compound with application in the pharmaceutical fields. Particularly, much attention has been focused of the used of layered double hydroxides as support for controlled release systems of drugs, vitamins, biomolecules, etc. Layered double hydroxides or anionic clays, hydroxides sheets consist of positively charged 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). In the indirect route was prepared first the host laminar solid and then the desired anion is introduced by contact a determinate time with stirring and temperature. Sodium diclofenac is a non-steroidal antiimflamatory drugs 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 calorimetric thermogram of sodium diclofenac present two endothermic peaks at 270°C and 350°C due to the melting point and the oxidative of degradation. Differential scanning calorimetric 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 is observed. This behavior indicated a thermal stabilization of the drug.