Preparation of controlled release nanodrug ibuprofen supported on mesoporous silica using supercritical carbon dioxide

Deposition of ibuprofen (IBU) into ordered mesoporous silica SBA-15 was carried out to prepare controlled release nanodrug using supercritical carbon dioxide (scCO2) as solvent at 17 MPa and 310.15 K. The maximum drug loading of IBU/SBA-15 was as high as 41.96%. The characterization of the obtained materials was performed using x-ray diffractometry (XRD), scanning electron microscopy (SEM), and nitrogen (N2) adsorption-desorption isotherms; the results indicate that most adsorbed drugs were inside the nanoscale channels. The in vitro study shows that the time of complete (100%) release significantly decreases as drug-loading decreases. The interesting aspect is that the samples with similar drug loading display different release rates, which may be due to differences in the drug quantity adsorbed inside the pores. In addition, the modified Noyes-Whitney equation was used to model the release kinetics for all the samples and a good agreement was obtained between the model representation and experimental data. In addition, the solubility of IBU in scCO2was tested through a high-pressure view cell at the temperature range of 298.15–320.15 K and pressure range of 7–17 MPa. The experimental solubility data were well correlated using Chrastil’s equation as well as Mendez-Santiago and Teja’s equation.