Estudo da intercalação de sulfadiazina de prata em hidróxido duplo lamelar de níquel e ferro

Abstract

Layered double hydroxides (LDH) are clayey materials of the hydrotalcite class and have a structure made up of layers formed by mixed hydroxides of two metal cations, structured in a two-dimensional stacking form. In recent years, it has been gaining greater prominence mainly due to its reconstruction and anion exchange properties, which allow the incorporation of biologically active substances that are negatively charged in the interlayer region. This property neutralizes positive charges, which generates not only the possibility of adsorbing positively charged materials on the HDL surface, but also of intercalating chemical species. The present work aimed to prepare and characterize NiFeLDH by coprecipitation route, evaluating the modification of its pH during synthesis and verifying its possible application as a carrier of the drug silver sulfadiazine (SDZ-Ag). The prepared materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Thus, it was possible to observe that the synthesis of NiFe-HDL by the selected method presents greater crystallinity and yield when the precursor solution is prepared with pH 9,0 and that this same HDL can be used in the anion exchange intercalation process. The intercalation of SDZ-Ag was confirmed by XRD, since there was a shift of the peak related to the basal plane (0 0 3) from 0.775 nm to 1.06 nm when aged in a 1000 ppm solution of the drug, and a decrease in the band at 1834 cm-1 that can be attributed to anion exchange. In the release test, the hybrid obtained an excellent response, since within 4 h it was able to stabilize the release rate of SDZ-Ag in aqueous medium and in PBS solution with pH set at 7,4, which demonstrates the potential for application of the material as a drug carrier.