Preparation, Characterization, and Safety Evaluation of a Submicron Emulsion Processed Using High-Pressure Homogenization to Protect Bitter Melon Seed Oil

Bitter melon seed oil (BMSO), as a by-product of bitter gourd fruit processing, is rich in active ingredients and has unique medicinal potential. However, its solubility and dispersibility in water are poor when used directly. Therefore, this study aims to develop an eco-friendly submicron emulsion containing BMSO for intravenous injection and evaluate its safety. The BMSO submicron emulsion (BMSOSE) was prepared by high-pressure homogenization. The size, polydispersity index (PDI), ζ-potential, Turbiscan stability index (TSI), apparent viscosity, and morphology were characterized; in addition, an in vitro hemolysis test and acute toxicity test in mice were investigated in detail to evaluate the emulsion. The results demonstrated that the formulation and technological parameters of the BMSOSE were as follows: BMSO, 8% (<i>w</i>/<i>w</i>); egg yolk lecithin, 1.2% (<i>w</i>/<i>w</i>); F-68, 0.2% (<i>w</i>/<i>w</i>); pH, 5.0; homogenization pressure, 600 Pa; and number of homogenization cycle, 9. The obtained BMSOSE droplets exhibited a spherical shape with uniform size distribution with an average diameter of 221.3 nm, a PDI of 0.2, and a ζ-potential of -36 mV. There was no significant change in the fatty acid composition of BMSO and the BMSOSE. The safety tests demonstrated that the BMSOSE had no signs of hemolysis and had no toxicity to mice with LD50 > 64 mL/kg. This study provides a foundation for further development of BMSO and its preparations.