Fabrication of edible solid lipid nanoparticle from beeswax/propolis wax by spontaneous emulsification: Optimization, characterization and stability

Abstract

In the current study, the production and characterization of novel solid lipid nanoparticles (SLNs) using safe/lowcost natural beeswax (BW) and propolis wax (PW) and by the simple and inexpensive assay of spontaneous emulsification were studied. To fabricate SLNs, the optimum levels of surfactant/oil ratio (SOR), stirring speed, and time were obtained based on minimum particle size (PS) and polydispersity index (PDI). Therefore, the optimal conditions to produce PW and BW nanoparticles were SOR of 1.26 and 2 under stirring speed of 1050 rpm for 20 min, leading to PS of 21.9 and 23.2 nm, respectively. The contact angle of 73.7 degrees and 62.9 degrees for BW and PW SLNs respectively, showed suitable hydrophilicity to stabilize oil-in-water (O/W) Pickering emulsions. Temperatures over 70 degrees C led to a drastic increment of PS in both types of SLNs. Upon nanoparticles drying, the utilization of cryoprotectants could cause less aggregation and better reconstitution.