2.1. Development of Curcumin Solid Lipid Nanoparticles (CSLNs)

The CSLNs were prepared by a hot high-pressure homogenization method. The curcumin (0.6% w/w in the final formulation) was dissolved in polyethylene glycol (PEG) 600 followed by the addition of molten Compritol^® 888 ATO. A primary crude emulsion was prepared by emulsifying this hot lipid phase with the aqueous surfactant phase containing Tween 80 and Phospholipon 90G (soya lecithin), maintained at a temperature 5–10 °C above the melting point of Compritol^® 888 ATO (70 °C to 75 °C) using a high-speed stirrer (WiseTis HD 15D, Am Bildacker 16, 97877 Wertheim, Germany) at 8000 rpm for 8 min. The coarse emulsion was subjected to high-pressure homogenization (HPH) using the Emulsiflex C3 Avestin (2450, Don Reid Dr. Ottawa, ON, Canada) homogenizer at 1000 bars and three cycles. The dispersion obtained was allowed to cool to room temperature, forming lipid nanoparticles by re-crystallization of the hot dispersed lipid.