Scalable solvent‐free production of liposomes

Objectives A major challenge faced with the manufacture of liposomes is the high volumes of organic solvents used during manufacturing. Therefore, we have implemented an organic solvent‐free production method for drug‐loaded liposomes and demonstrated its applicability with both aqueous core‐loaded and bilayer‐loaded drugs. Methods Liposomes were produced by high shear mixing dry powder lipids with an aqueous buffer, followed by down‐sizing using a Microfluidizer processor. Liposomes were purified via tangential flow filtration and characterised in terms of size, polydispersity index, zeta potential and drug loading. Key findings Doxorubicin‐loaded PEGylated liposomes can be manufactured using this solvent‐free method with particle sizes of 100–110 nm, low polydispersity index (PDI) (<0.2) and high drug loading (97–98%). If required, liposomes can be further down‐sized via microfluidic processing without impacting drug loading. Similar results were achieved with non‐PEGylated liposomes. With bilayer‐loaded amphotericin B liposomes, again liposomes can be prepared within a clinically appropriate size range (100–110 nm in size, low PDI) with high drug loading (98–100%). Conclusions We apply a simple and scalable solvent‐free method for the production of both aqueous core or bilayer drug‐loaded liposomes.