Bioavailability of encapsulated resveratrol into nanoemulsion-based delivery systems

Different O/W nanoemulsion-based delivery systems were developed in order to optimize the bioavailability of encapsulated resveratrol for potential oral administration. Blank formulations without resveratrol had no negative effect on cell viability or the cytoskeleton structure of Caco-2 cells (XTT viability assay and confocal microscopy). All nanoemulsions were then evaluated based on permeability tests on Caco-2 cells. As a result, the most efficient formulations were lecithin-based nanoemulsions which were able to transport resveratrol through cell monolayers in characteristically shorter times (1-6 h) than those required for their metabolization (3-12 h), allowing for better preservation of the integrity of the emulsion droplets, thus better protecting the resveratrol molecule. Fluorescence spectroscopy studies confirmed that resveratrol was encapsulated in the inner core of the nanoemulsions, which provides protection against chemical degradation. Furthermore, the developed systems also demonstrated the capability of nanoemulsions in sustained release of resveratrol from dialysis bags compared to the unencapsulated compound.