Budesonide and salbutamol-loaded liposomes were prepared using an innovative one step supercritical CO2
method without any use of organic solvents. Liposomes composed of soybean phosphatidylcholine, cholesterol
and PEGylated lipid (65/30/5% (m/m)) were produced with a size less than 200 nm, a PdI within the range of
0.3 and 0.35 and encapsulation efficiency for budesonide and salbutamol reaching to 94% and 40% respectively.
The physical stability of the formulation was improved by optimizing a dry form by freeze-drying with trehalose
in a 20:1 (trehalose:lipid) ratio and an increase in the percentage of PEGylated lipid from 5% to 15%. This dry
form stored at 4 ◦C maintains 90–110% of the initial concentration of active compounds. The concentration of
budesonide and salbutamol after 15 weeks was 522.92 ± 73.01 μg/mL and 144.86 ± 31.22 μg/mL respectively.
These concentrations are close to the concentrations of these molecules in the pharmaceutical products Pulmicort
® (500 μg/mL of budesonide) and Ventolin® (100 μg/dose). The formulation tested on lung cells, allows a
cell viability of 71 ± 6%, which is not significantly different from untreated cells.

Liposome Co-encapsulation Supercritical carbon dioxide Green process Drug delivery Budesonide Salbutamol