Influence of drug properties on loadings and release kinetics of drugs from silica aerogels loaded in supercritical CO2

Insights into Adsorptive Drug Loading on Silica Aerogels from Supercritical CO2

“…Similar trends in the loading are expected if the system was depressurized at faster or slower rates than that corresponding to those in Figure . In fact, our earlier work showed that larger amounts of drugs precipitate if the pressure is released slowly than quickly.…”

“…The amount of fenofibrate precipitated on the aerogels is calculated from the difference between its respective loadings without flushing and with flushing. Figure shows that the loading by precipitation of fenofibrate rises linearly with its concentration in the scCO 2 phase as precipitation is due to its nucleation and growth, and most of the precipitation is contributed by growth, which is linearly dependent on concentration …”

“…Figure 4 shows that the loading by precipitation of fenofibrate rises linearly with its concentration in the scCO 2 phase as precipitation is due to its nucleation and growth, and most of the precipitation is contributed by growth, which is linearly dependent on concentration. 34 Figures 5 and 6 7 This section proposes a mechanism for drug loading without flushing, as depicted in the graphical abstract, presuming the possibility of precipitation on the adsorbed drug molecules forming a monolayer on silica aerogels; these adsorbed molecules presumably act as the active sites for heterogeneous nucleation at low concentrations. In addition, there is a possibility of additional precipitation by nucleation on the active sites of aerogels outside the monolayer adsorbed molecules as well, at relatively higher concentrations.…”