Microfluidic methods and systems are provided for continuous flow synthesis and active loading of liposomes, which include a liposome formation region configured to form a population of liposomes and a microdialysis region downstream from the liposome formation region and configured to form a transmembrane gradient for active drug loading of the liposomes. Microfluidic methods and systems for high throughput production of liposomes are also provided featuring high aspect ratio microchannels.