Stabilization of solid lipid nanoparticles with glycyrrhizin

Abstract

This study investigated the influence of saponin glycyrrhizin on the formation and stability of solid lipid nanoparticles. The hypothesis was that glycyrrhizin facilitates the formation of stable crystalline lipid particles due to its molecular characteristics and slows down polymorphic transition. Tristearin solid lipid nanoparticles emulsified with glycyrrhizin at varying concentrations at pH 7 and 3 were generated by hot high-pressure homogenization. The influence of glycyrrhizin on the physical stability and crystallization behavior of solid lipid nanoparticles was evaluated by dynamic and static lights scattering, electrophoretic light scattering, optical microscopy, visual observations, and differential scanning calorimetry. The results showed that glycyrrhizin formed nanosized solid lipid nanoparticles at both pH 7 and 3. The glycyrrhizin concentration and the pH applied governed the crystallization behavior and the polymorphic stability as well as the physical appearance. Overall, glycyrrhizin showed remarkable ability to stabilize solid lipid nanoparticles against polymorphic transition over time. These results are relevant for food, pharmaceutical, and cosmetic industries to form stable carrier systems by using natural plant-based saponins as surfactants.