Preparation and characterization of SLNs (W/O/W type) contained lipoic acid PEG ester by variation lipid

This study describes a nanoparticle preparation method using SLNs (solid lipid nanoparticles: W/O/W type). Classical methods have high encapsulation efficiency for hydrophobic drugs but have low encapsulation efficiency (2–3%) for hydrophilic drugs. The preparation of SLNs that has a far higher skin penetration effect compared with general liposomes is proposed in this study. An additional aim is to also maximally increase encapsulation efficiency of hydrophilic drugs. The SLNs preparation method described here used coconut oil, jojoba oil and macadamia oil that are resistant to degradation by microorganisms and are usable emulsifiers due to their physical properties imparted by their fatty acid composition. The results indicate that SLNs containing coconut oil had the highest encapsulation efficiency and also the smallest average particle size (270 nm). The largest particle size was produced by macadamia oil and 1% Tween 60. The fastest release of contents resulted from SLNs made of coconut oil and 2% Tween 60, while the slowest release was from SLNs made of macadamia oil and 2% Tween 20.