phase inversion

Unrefined shea butter is a vegetable fat that can be used for its anti-inflammatory properties related to its unsaponifiable fraction but also as excipient for various forms. In this study, the aim was to see how to take advantage of this dual status in order to improve the anti-inflammatory activity of shea butter through nanotechnology. In other words, it was to test the hypothesis of an improvement of the anti-inflammatory activity of unrefined shea butter when used in the form of nanoparticles  and gel / nanoparticle system. The nanoparticles were prepared by a phase inversion method and had an average size of 400 nm with a poly dispersion index of 0.416, a zeta potential between -5 and -7mV and a pH around 5.3-5.4. The gel / nanoparticle complex was obtained by mixing the nanoparticles with a gel based on polyethylene glycol, water and HydroxyPropyl Methylcellulose. The mouse ear edema test was implemented for the evaluation of the anti-inflammatory activity and the results showed a clear improvement of the latter. Indeed, the ratios (R) between the percentage inhibition of the anti-inflammatory activity (I) and the real percentage of shea butter used in the various preparations are respectively: crude shea butter (I = 62.52%; R = 0.62), nanoparticles (I = 60.80%, R = 1.05) and gel / nanoparticle complex system (I = 52.41, R = 6.38) (for the latter, the proportion of nanoparticles in the complex system was 4/24). Keywords: Shea butter, phase inversion, lipid, nanoparticles, nanoparticle/gel complex, anti-inflammatory activity