Multianalytical characterisation and the drug release profile of silica-based gels


Xerogels can be described as dried gels that retain their porous structure after the drying procedure. They’re characterised by mesoporosity and a peculiar structure that can easily be controlled during the synthesis procedure. Silica-based xerogels are exciting material in different applications sectors such as gas storage and separation, biocatalysis, corrosion protection, adsorption of organic solvents. Drug delivery is also a relevant field of applications for silica xerogels because of their biocompatibility, high loading efficiency, and low processing temperature.

In the framework of national and international cooperation, the group led by Dr. Zoltán Dudás (Centre for Energy Research, Budapest) headed a scientific work characterised by a multi analytical study of silica xerogels prepared at different pH and with varying ratios of precursors. Numerous CERIC techniques were employed to analyse the gels, such as Small-Angle Neutron Scattering (SANS), lab Small-Angle X-ray Scattering (SAXS), High-Resolution Transmission Electron Microscopy (HRTEM), and solid-state Nuclear Magnetic Resonance (NMR), giving fundamental insights into the structure, composition, and synthesis of the silica xerogel. These techniques are available respectively at the Hungarian, Austrian, Romanian, and Slovenian CERIC partner facilities. Following the characterisation, xerogels were tested for the uptake and release of Captopril, a well-known molecule employed in the treatment of hypertension and some types of heart failure.

The quantity of methyl functionalization modifies the primary particles size and the shape and size of the pores

This study allowed to gain essential information about the structural and physicochemical characteristics of silica xerogels and how the pH and the precursors ratios impact the final structure. The loading and release experiment revealed that the synthesis procedure could affect the release profile of the drug, being connected with the apparent surface area. This study gave essential information for developing technologies in several fields, including drug release, with a relevant impact on future medical treatments.


Physicochemical Characterization and Drug Release Properties of Methyl-Substituted Silica Xerogels Made Using Sol–Gel Process. Len A., Paladini G., Románszki L., Putz A-M, Almásy L., László K., Bálint S., Krajnc A., Kriechbaum M., Kuncser A., Kalmár J. & Dudás Z., International Journal of Molecular Sciences, 2021.