Formation and characterization of hydrogenated soybean lecithin/TPGS nano-dispersions as a potential carrier for active herbal agents

Abstract

The goal of this study was to examine the effects of lipid composition on physicochemical characteristics of hydrogenated soybean lecithin (HL)/d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) dispersions using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, and fluorescence polarization spectroscopy. Our results showed that HL-rich nano-dispersions exhibited larger size, narrower size distribution, higher negative zeta potential, more obvious phase transition regions, and lower membrane fluidity than did the TPGS-rich ones. The membrane packing order, intermolecular attraction interaction, and molecular cooperativity in the phase transition region of the HL dispersions could be reduced by the incorporation of a large amount of TPGS. Furthermore, chemical stability, a drug release profile, and free radical-scavenging capacity of HL/TPGS nano-dispersions encapsulating black soybean seed coat extract (BE) were analyzed. HL/TPGS nano-dispersions improved the stability and radical-scavenging capacity of phytochemicals, such as BE. Nano-dispersions with the molar ratio of HL/TPGS = 9/1 exhibited good storage stability, a slow BE release rate, good free radical-scavenging capacity, and high in vitro biocompatibility; thus, they could be a high-potential vehicle for carrying active herbal agents.