Spectroscopic, Thermal Analysis and Bioactivity Study of New Ferrous Citrate Based Materials Prepared by Sol–Gel Method

The aim of this work is the development of a system able to release ferrous ions in a controlled manner. An interesting alternative to a systemic therapy can be the use of controlled drug release for medical applications. Starting from iron powder and citric acid, ferrous citrate (Fe(II)C) is synthesized by a redox reaction between these two. The confirmation that only Fe(II)C is obtained by redox reaction is shown from Fourier transform infrared spectroscopy (FTIR), 1,10-phenanthroline and sodium thiocyanate colorimetric experiments. Fe(II)C is embedded within a SiO2 matrix in different weight percentage by means of a sol–gel route. The presence of Fe(II)C in the silica matrix is confirmed by FTIR spectroscopy and thermogravimetry assays. Furthermore, these two techniques are used to investigate the thermal behavior of the above-mentioned sol–gel materials. The bioactivity test carried out by soaking the synthesized complex delivery systems in a simulated body fluid shows that the biological properties of the silica matrix are not modified by the presence of Fe(II)C.