A supercritical fluid technology for liposome production and comparison with the film hydration method

Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific parameters (lipid concentration, dispersion volume, agitation rate, temperature and pressure) allowing the production of liposomes with predicted physicochemical characteristics (particles size and PdI). Two conditions were determined with specific production parameters. It was shown that these two conditions allowed the production of liposomes of different compositions and that most of the liposome formulations had size and dispersity in accordance with the prediction values. The condition involving the higher lipid concentration showed a higher variability in terms of size and dispersity. However, this variability remained acceptable. This innovative supercritical method allowed the production of liposomes with physicochemical characteristics similar to those obtained by the conventional thin film hydration method. This new supercritical carbon dioxide method easily scalable in GMP conditions is a one-step production method contrarily to conventional methods which generally need an additional step as extrusion to homogenize the size of liposomes.