Cationic liposomes in double emulsions for controlled release

► Double-encapsulation formulations were fabricated by incorporating liposomes as the W1 phase of W1/O/W2 double emulsions. ► Cryo-SEM images showed that liposomes are well encapsulated within the W1 phase. ► The release mechanism upon the freeze-thaw treatment is internal coalescence followed by external coalescence. ► The release of liposomes and FITC-BSA upon the freeze-thaw treatment is gradual rather than instant from the W1 phase. ► The release rate can be controlled by tuning the concentration of PC lipids in the liposomes.