Application of Response Surface Methodology for the Optimization of β-Carotene-Loaded Nanostructured Lipid Carrier from Mixtures of Palm Stearin and Palm Olein

The main purpose of this study was to optimize a beta-carotene-loaded nanostructured lipid carrier (beta C-NLC) using the lipid matrix of palm stearin and palm olein and Tween 80 as a surfactant. The NLC was prepared by using the high shear homogenization method. Box-Behnken Design (BBD) response surface methodology (RSM) was applied to optimize the process and formulation. A three-factor experimental model was used to optimize the combination of palm stearin ratio (A, %w/w), lipid:surfactant ratio (B, %w/w), and (lipid+surfactant):water ratio (C, %w/w). The formulations were evaluated for their responses on particle size (Y1), polydispersity index (Y2), zeta potential (Y3), and encapsulation efficiency (Y4). Subsequently, Fourier-transform infrared spectroscopy (FTIR), thermal (DT-TGA), x-ray diffraction (XRD), transmission electron microscopy (TEM), and in vitro release (Franz diffusion cell) analyses were utilized to observe the resulting optimum formulation. The optimum formulation was obtained at a combination of A (5.5:4.5), B (1:4.9), and C (24:76) %w/w. This resulted in beta C-NLC having a particle size of 166 nm, polydispersity index of 0.35, zeta potential of -26.9 mV, and an encapsulation efficiency of 91.2%. No strong interaction between different NLC components was observed based on FTIR, DT-TGA, and XRD profiles. Round-shaped NLC particles were observed under TEM. Franz diffusion cell observation resulted in diffusion profile of beta-carotene of 110.6 mu g cm(-2) with a flux of 1.06 (mu g cm(-2) hour(-1)). This indicates that palm stearin and palm olein can be prospectively developed as beta C-NLC.