Shellac/caseinate as a composite nanocarrier for improved bioavailability of quercetin

In the present study, quercetin (a flavonoid) was encapsulated using biodegradable composite polymers of sodium caseinate and shellac for its improved bioavailability. The quercetin-loaded shellac-caseinate composite nanoparticles (QSNPs) were prepared by anti-solvent precipitation method. Under the optimal combinations of process factors (sodium caseinate 2.5%, shellac 2% and pH 6.8,) the nanocomplexes had the sizes, PDI, zeta potential and encapsulation efficiency of 222 ± 0.19 nm, 0.11, -33.6 mV and 79%, respectively. The optimised nanocolloids were characterised using SEM and AFM microscopes for morphological features. The in vitro release study in simulated gastric and intestinal fluids showed a sustained release of the quercetin from the nanostructures. In rats, the oral administration of single equivalent dosage of quercetin (50 mg/kg b.wt) showed 18.6-fold increase in the relative bioavailability for QSNPs compared to suspension form. These results suggest that the composites of shellac/caseinate matrices can be promising carrier for the oral delivery of hydrophobic phytocompounds with enhanced therapeutic properties in various foods and pharmaceutical applications.