Liposomes are very interesting drug delivery systems for pharmaceutical and therapeutic purposes. However,
liposome sterilization as well as their industrial manufacturing remain challenging. Supercritical carbon dioxide
is an innovative technology that can potentially overcome these limitations. The aim of this study was to optimize
a one-step process for producing and sterilizing liposomes using supercritical CO2. For this purpose, a
design of experiment was conducted. The analysis of the experimental design showed that the temperature is the
most influential parameter to achieve the sterility assurance level (SAL) required for liposomes (≤10􀀀 6). Optimal
conditions (80 ◦C, 240 bar, 30 min) were identified to obtain the fixed critical quality attributes of liposomes. The
conditions for preparing and sterilizing empty liposomes of various compositions, as well as liposomes containing
the poorly water-soluble drug budesonide, were validated. The results indicate that the liposomes have appropriate
physicochemical characteristics for drug delivery, with a size of 200 nm or less and a PdI of 0.35 or less.
Additionally, all liposome formulations demonstrated the required SAL and sterility at concentrations of 5 and
45 mM, with high encapsulation efficiency.

Liposome, Supercritical carbon dioxide, Green process, Quality by design, Production, Sterilization, One-step process, Encapsulation