Conventional and novel methods for the preparation of micro and nanoliposomes

Liposomes mainly comprise an aqueous core surrounded by a lipid bilayer, akin to cellular membranes. The encapsulation, loading, and release properties of therapeutic agents in both, the core and lipid bilayer can be prominently affected by the preparative processes for liposome which include hydration of lipid thin films, detergent removal, solvent injection, reverse phase evaporation, emulsion, microfluidic methods (micro hydrodynamic focusing, microfluidic droplets and pulsed jet flow microfluidics), among others. Each method has its advantages and disadvantages for loading various hydrophilic and hydrophobic drugs. Therefore, selecting an appropriate method for the synthesis of micro- and nano liposome is a critical issue, particularly on the large-scale commercial enterprise. Herein, the main aim of this review is to present and compare the relative advantages of conventional and novel preparative methods of liposome in view of the emerging trend in their utilization. As the main conclusion, a combination of methods, for instance, supercritical fluids (SCFs) and microfluidic approaches can be employed along with emulsion method to synthesize micro and nanoliposomes encapsulated lipophilic drugs.