Nanostructured lipid carriers of Mucuna pruriens extract composed of cetyl palmitate and oleic or linoleic acid

Mucuna pruriens (MP) seeds are a natural source of levodopa, but the stability and delivery of their bioactive constituents may be limited in conventional formulations. This study developed MP extract-loaded nanostructured lipid carriers composed of cetyl palmitate and either oleic acid (OA-MP) or linoleic acid (LA-MP). The MP extract contained 26.02% levodopa, as determined by HPLC. The formulations were optimized by varying the solid-to-liquid lipid ratio and ultrasonication power. Increasing the liquid-lipid proportion reduced particle size, with a 4:6 solid-to-liquid lipid ratio selected for further optimization. Increasing ultrasonication power from 15% to 75% markedly decreased particle size and polydispersity. At 75% ultrasonication power, OA-MP and LA-MP exhibited particle sizes of 125.47 ± 1.20 nm and 149.43 ± 1.16 nm, respectively, with a PDI of 0.25 ± 0.02 for both formulations. Their zeta potentials were − 14.1 mV for OA-MP and − 13.5 mV for LA-MP. OA-MP showed higher entrapment efficiency and loading capacity (69.81 ± 0.60% and 4.25 ± 0.50%) than LA-MP (55.26 ± 0.50% and 3.37 ± 0.50%). At pH 7.4, LA-MP exhibited a higher cumulative MP extract release after 420 min (86.66 ± 0.40%) than OA-MP (62.11 ± 0.40%), whereas release at pH 1.2 was limited to 18.38 ± 0.40% and 14.03 ± 0.50%, respectively. These findings demonstrate that ultrasonication power and liquid lipid composition substantially influenced particle characteristics, encapsulation performance, and release behavior. Oleic acid favored extract retention, whereas linoleic acid promoted greater release at pH 7.4.