Influence of different solid lipids on the properties of a novel nanostructured lipid carrier containing Antarctic krill oil

This study aimed to investigate the effect of solid lipids (lauric acid (LAU), myristic acid (MYR), stearic acid (STE), glycerol monostearate (GMS), glycerol 1,3-distearate (GDS), glycerol tristearate (GTS), glycerol trimyristate (GTM) and glycerol trilaurate (GTL)) on the characteristics of novel nanostructured lipid carrier (NLC) containing Antarctic krill oil through ultrasound. The fatty acids (LAU, MYR, STE and GMS) were unsuitable solid lipid materials, as apparent stratification was quickly observed during the NLC preparation. NLCs were successfully prepared using GTS, GTM, GTL and GDS. The zeta potential of all NLCs exceeded -30 mV indicating good uniformity and stability. These NLCs appeared spherical or oval. Differential calorimetry and X-ray diffraction analysis revealed these NLCs formed imperfect crystals. As the carbon chain length of triglycerides increased from C-12 to C-18, the particle size of NLCs increased from 235.8 +/- 2.3 nm to 340.5 +/- 2.2 nm, the degree of recrystallisation increased from 39.06% to 49.99%, while the EPA encapsulation efficiency decreased from 88.72 +/- 0.47% to 72.86 +/- 1.06%. NLC prepared with GDS had the smallest particle size (112.4 +/- 0.4 nm), the lowest recrystallisation and the highest EPA encapsulation efficiency (>99%). GDS was the most suitable to prepare high encapsulate efficiency krill oil-loaded NLC.