The exploration of biocompatible and sustainable materials for nanotechnology-based formulations with pharmaceutical and cosmetic applications is rapidly expanding. Among these formulations, solid lipid nanoparticles (SLNs) have garnered significant attention due to their biocompatibility and potential to enhance transcutaneous penetration, rendering them suitable for skin applications [1]. However, they present some issues, such as low stability. On the other hand, biobased ionic liquids (ILs) are versatile compounds, known to improve the incorporation of sparingly soluble compounds, improve stability, or enhancepermeation across the skin barrier [2]. Therefore, their incorporation in nanodelivery systems has the potential to improve the overall properties of nanoparticles. This work aimed to produce and evaluate the performance of SLNs incorporating choline-based ILs.

Different SLNs were prepared using two commercial lipids, Gelucire® 43/01 and Precirol ATO® 5. Moreover, (2-hydroxyethyl)trimethylammonium phenylalaninate – [Cho][Phe] was incorporated in both types of SLNs. The nanosystems were characterized concerning size, polydispersity index, and zeta potential. Stability studies were conducted for 90 days. Additionally, the impact of the nanoparticles on cell viability was also evaluated using the HaCaT cell line via the MTT assay.

The results showed that ILs improve the colloidal stability of the nanoparticles and the physicochemical properties towards a topical application. The data also showed that the impact of ILs is dependent on the solid lipid used to prepare the SLNs. In conclusion, the production of innovative lipid nanocarriers combined with biobased ILs seems to open a new paradigm for skin delivery.