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Abstract :
[en] Sterility is a requirement for parenteral administration of liposomes. However, conventional sterilization methods of liposomes have limitations. Supercritical Carbon Dioxide (ScCO2) is a promising strategy for the sterilization of sensitive products. In this work, the effects of ScCO2 sterilization conditions on physicochemical characteristics of liposomes were investigated using a liposome formulation previously validated in the LPTB. This model formulation contains cholesterol, dimethylaminoethane-carbamoyl hydrochloride (DC-cholesterol), egg phosphatidylcholine (EPC) and distearoylphosphatidylethanolamine (DSPE) PEG2000, and as active drug, apigenin. Liposomes were prepared by thin-film hydration method and the physicochemical characteristics such as pH, particle size, polydispersity index (PDI), zeta potential, amount of encapsulated apigenin and phospholipids concentration were determined before and after submission to the selected ScCO2 sterilization conditions: 70 ° C, 150 bar for 4h (Karajanagi and al, 2011). The results showed a decrease of the pH of the dispersion, the size, the zeta potential of the vesicles and of the amount of encapsulated apigenin. On the contrary, an increase in PDI after treatment with ScCO2 was observed. In spite of changes observed with this liposome formulation under sterilization conditions used in this work, others conditions should be tested in order to maintain the characteristics of the formulations before and after the sterilization process.