Preparation of solid lipid nanoparticle formulations

FP-loaded SLN formulations were manufactured using a high pressure homogenizer. Tristearin was melted and 50 mg of FP was added to the melted lipid. Aqueous Tween 80 (1%) solution was also heated to the same temperature. After an Ultraturrax T25 (IKA, Germany) at 13.500 rpm was used to mix the lipid phase and aqueous phase for 3 min, the hot pre-emulsion was subsequently homogenized by a Microfluidics M110L (USA) at a pressure of 18.000 Psi. Three different tristearin percentages (1%, 2%, and 4%) and three different cycle numbers (2, 4, and 8 cycles) were investigated based on two responses: encapsulation efficiency (Q1) and particle size (Q2). SLN dispersions were centrifuged using a Vivaspin (MWCO=10.000) at 4500 rpm for 30 min (Sigma 3K30, Germany) and then lyophilized.