Rapid and scale-independent microfluidic manufacture of liposomes entrapping protein incorporating in-line purification and at-line size monitoring.

Within this paper we present work that has the ability to de-risk the translation of liposomes from bench to the clinic. We have used microfluidics for the rapid and scale-independent manufacture of liposomes and have incorporated in-line purification and at-line monitoring of particle size. Using this process, we have manufactured a range of neutral and anionic liposomes incorporating protein. Factors investigated include the microfluidics operating parameters (flow rate ratio (FRR) and total flow rate (TFR)) and the liposome formulation. From these studies, we demonstrate that FRR is a key factor influencing liposome size, protein loading and release profiles. The liposome formulations produced by microfluidics offer high protein loading (20-35%) compared to production by sonication or extrusion (<5%). This high loading achieved by microfluidics results from the manufacturing process and is independent of lipid selection and concentration across the range tested. Using in-line purification and at-line size monitoring, we outline the normal operating range for effective production of size controlled (60-100 nm), homogenous (PDI <0.2) high load liposomes. This easy microfluidic process provides a translational manufacturing pathway for liposomes in a wide-range of applications.