¹Department of Pharmaceutical Technology, Faculty of Pharmacy, Ankara University, Yenimahalle, 06560, Ankara, TURKEY DOI : 10.29228/jrp.29 Lipid nanoparticles (SLNs and NLCs) have possessed many advantages as versatile and innovative carriers to achieve better quality and highly effective skin-care cosmeceuticals. While they protect the water content of the epidermis by increasing skin occlusion, maintain the smoothness and elasticity of the skin, enhance the efficacy of the active substance by penetrating into the deep layers of the skin. Semi-solid lipid nanoparticles, which are the latest generation of lipid nanoparticles containing high amount of lipids compared to SLNs and NLCs are promising systems as nano-cosmeceuticals due to their semi-solid consistency and colloidal particle size. In this study, semi-solid lipid nanoparticles in NLC form were obtained by using different vegetable oils that possess positive effects in the dermal application. Then, the main in vitro physicochemical characteristics of the formulations that affect skin hydration like size, surface charge, and occlusive properties were investigated. Overall results suggested that, while vegetable oil loaded semi-solid lipid nanoparticles were obtained, colloidal size and semi-solid consistency could be maintained. On the other hand, all formulations had acceptable firmness values for customer use despite the high lipid content of the system, and enhanced skin hydration with the help of both vegetable oils and lipid nanoparticles were achieved. Keywords : Semi-solid lipid nanoparticles; nano-cosmeceuticals; vegetable oil; skin occlusion