Novel “Solid Lipid Pickering Particles” (SLPPs) for controlled drug delivery

Novel “Solid Lipid Pickering Particles” (SLPPs) are spherical lipid particles decorated with an embedded outer layer of nanoparticles (NPs). SLPPs present the solid version of Pickering emulsion (PE), known for over a century. These particles were prepared by emulsifying liquified melted solid lipid in an aqueous dispersion of NPs to form an oily emulsion. Upon cooling, the oil core in the hot emulsion solidifies to a solid-lipid core decorated with the surface embedded NPs. Silica, Fe₃O_4, TiO_2, ZnO, MgO, and hydroxyapatite NPs were used for the preparation of SLPPs. Contrary to the PE, the developed SLPPs are stable over time and can be isolated both as a dry re-dispersible powder or a re-dispersible concentrated slurry with a very high loading of an active ingredient (AI). Such loading of the AIs and long-term stability is unachievable with a conventional liquid oil-core PE. The shape and morphology of the SLPPs was confirmed by scanning electron microscopy (SEM) and Energy-dispersive X-ray analysis (EDAX). SLPP were used for controlled delivery of several AIs that have been constantly released in aqueous media for weeks. The proposed SLPPs have potential application in the controlled delivery of active agents in medicine, food, cosmetics, and agriculture.