Supercritical CO2 assisted process for the production of mixed phospholipid nanoliposomes: Unloaded and vitamin D3-loaded vesicles

In this study, SuperLip, an innovative technology assisted by supercritical carbon dioxide (SC–CO2), was used to produce unloaded and vitamin D3 (VD3)-loaded nanoliposomes. Vesicles were produced using hydrogenated and nonhydrogenated phosphatidylcholine from food-grade lecithins at ratios of 30:70, 20:80 and 0:100. SuperLip was operated at 100 bar and 40 °C using water flow rates ranging from 2.5 to 10 mL/min. The results showed that unloaded liposomes produced by SuperLip presented a unimodal size distribution at a water flow rate of 10 mL/min, regardless of the phospholipid ratio, and mean diameters ranging from 125 to 141 nm. VD3-loaded liposomes also presented a unimodal size distribution at this water flow rate, but slightly higher diameters that ranged from 144 to 252 nm. Furthermore, the addition of 20% purified phospholipids to liposomes led to an increase in the mean size of VD3-loaded vesicles from 144 to 218 nm and an increase in the encapsulation efficiency from 66.7 to 88.9%.