Synthesis and biotriborheological characterization of shea butter solid lipid nanoparticles in topical formulation

Abstract

Solid Lipid Nanoparticles (SLN) are pharmaceutical delivery system and pharmaceutical formulation that provide great biocompatibility and efficiency of encapsulation. The current challenge is the storage of these due to the time they agglomerate reducing their properties. An effective way to validate its stability in storage is conducting rheology studies. Shea Butter SLN is used, with the purpose of having a higher antioxidant effect. It has been performed the synthesis, by hot homogenization technique, with an excellent stability. We validated its penetration capacity and perform different characterizations as for example Atomic Force Microscopy (AFM), Confocal Microscopy, Scanning Electron Microscopy (SEM), DSC, DLS and Zeta potential. It gave us an mean particle size of 213 nm, with a zeta potential of -40 mV and obtaining a circular morphology; Therefore, we can affirm that a correct synthesis of these nanoparticles was carried out, due to their size and stability since after 3 months of storage they did not show significant growth. Because of Confocal Microscopy studies, due to their property that SLNs are autoflowering, it was possible to validate that Shea Butter Solid Lipid Nanoparticles can penetrate the epidermis. Triborheological studies were carried out such as Oscillatory stress sweep, Viscosity/shear rate profile, Normal stress profile and Sliding speed sweep in this way we identify and quantify the impact of Solid Lipid Nanoparticles in topical formulations. It was discovered that SLNs had lower Coefficient of Friction than those containing bulk lipids. SLNs in topical formulations have potential applications in the cosmetic as anti-aging agents this due to its antioxidant properties, skin occlusion, increased skin hydration and potential antiinflammatory properties.