Preparing glabridin-in-water nanoemulsions by high pressure homogenization with response surface methodology

Glabridin is a pharmacological active hydrophobic pyranoisoflavan isolated from licorice. It has low bioavailability and solubility and therefore is difficult to apply for industry use. We investigated the effect of combining caprylic triglyceride with glabridin (2-6%, w/w), emulsifier (3-7%, w/w), and homogenization pressure (70-130 MPa) on the droplet size of glabridin nanoemulsions using response surface methodology by a 3-factor-3-level Box-Behnken design. Oil content, emulsifier content and pressure had a significant effect on droplet size (p < 0.05). The optimal conditions for preparing glabridin nanoemulsions were predicted to be caprylic triglyceride (oil content), 3.7%; emulsifier content, 5.3%, and homogenization pressure, 129 MPa.