The method chosen for the preparation of the nanoparticles was a good compromise between the high shear homogenization to produce particles in the micrometer range and the ultrasound method to reduce the microparticles to the nanometer range. For the SLNs cetyl palmitate and polysorbate 60 were added. In the case of NLCs cetyl palmitate, polysorbate 60, and the liquid lipid miglyol-812 were added (Table 1 ).
The lipid phase, containing cetyl palmitate, miglyol-812, the stabilizer polysorbate 60, and the lipophilic resveratrol to be encapsulated (0, 2, 5, 10, and 15 mg), was melted at 70°C, which was above the lipid’s melting point. The molten lipid was then dispersed in Milli-Q water at the same temperature by high-speed stirring in an Ultra-Turrax T25 (Janke and Kunkel IKA-Labortechnik, Staufen, Germany) followed by sonication using a Sonics and Materials Vibra-Cell™ CV18 (Newtown, CT, USA). Some parameters of the high shear homogenization and ultrasound method technique for the lipid nanoparticles production were optimized in order to establish the best conditions for the production of each type of formulation. The SLNs were stirred for 30 seconds at 12,000 rpm, followed by 5 minutes of 80% intensity sonication. The NLCs were homogenized for 2 minutes then sonicated during 15 minutes at 70% intensity.
The formulations appeared white and milky and had low viscosity. The cooling of the nanoemulsions at room temperature allowed the crystallization of the lipid and subsequent formation of the lipid nanoparticles. To assess the stability of the formulations, they were stored for 2 months at room temperature and the particle size and zeta potential were measured periodically.
The lipid phase, containing cetyl palmitate, miglyol-812, the stabilizer polysorbate 60, and the lipophilic resveratrol to be encapsulated (0, 2, 5, 10, and 15 mg), was melted at 70°C, which was above the lipid’s melting point. The molten lipid was then dispersed in Milli-Q water at the same temperature by high-speed stirring in an Ultra-Turrax T25 (Janke and Kunkel IKA-Labortechnik, Staufen, Germany) followed by sonication using a Sonics and Materials Vibra-Cell™ CV18 (Newtown, CT, USA). Some parameters of the high shear homogenization and ultrasound method technique for the lipid nanoparticles production were optimized in order to establish the best conditions for the production of each type of formulation. The SLNs were stirred for 30 seconds at 12,000 rpm, followed by 5 minutes of 80% intensity sonication. The NLCs were homogenized for 2 minutes then sonicated during 15 minutes at 70% intensity.
The formulations appeared white and milky and had low viscosity. The cooling of the nanoemulsions at room temperature allowed the crystallization of the lipid and subsequent formation of the lipid nanoparticles. To assess the stability of the formulations, they were stored for 2 months at room temperature and the particle size and zeta potential were measured periodically.
