Preparation and Characterization of Nanostructured Lipid Carriers (NLCs) Formulated with Palm Kernel Stearin and Rice Bran Oil as Squalene Carriers Via Ultrasonication

This study aimed to optimize the synthesis of squalene-loaded nanostructured lipid carriers (NLCs) using a mixture of palm kernel stearin and rice bran oil as the lipid matrix and Tween 80 as the surfactant. NLCs were prepared via ultrasonication. Optimization was performed using Box–Behnken Design response surface methodology. Ultrasonication parameters assessed included temperature, time, and amplitude. The effect of optimization on particle size (X1), polydispersity index (X2), zeta potential (X3), and encapsulation efficiency (X4) was determined. Nine tests were conducted on squalene-loaded NLCs and control samples over 28 days of storage. These NLCs were prepared at an ultrasonication time of 24.8 min amplitude of 80, and temperature of 43.7°C. NLC characteristics were evaluated before and after storage for 28 days at room temperature, which resulted in particle size of 38.6 and 40.3 nm, polydispersity index (PDI) of 0.282 and 0.213, zeta potential of −34.1 and −34.8 mV, and encapsulation efficiency of 85.69 and 84.04, respectively; empty NLCs had a particle size of 37.4 and 38.5 nm, PDI of 0.240 and 0.276, and zeta potential of −41.5 and −32.9 mV. Copyright © 2025 by Indonesian Journal of Pharmacy (IJP).