Doxorubicin (DOX)-loaded water-in-oil-in-water (W/O/W) microemulsions were produced using a shirasu-porous-glass (SPG) membrane emulsification technique. Soybean oil was used as the oil phase; polyglycerol polyricinoleate (PGPR) or tetraglycerol polyricinoleate (TGPR) was used as the surfactant to stabilize the feed W/O emulsions, while Tween 20 was used in the external water phase to stabilize...