A novel method for preparing liposome with a high capacity to encapsulate proteinous drugs: Freeze-drying method.

A simple method for the preparation of liposome with high encapsulation efficiency was developed. A solution of L-asparaginase (A-ase) and a sonicated phospholipid were mixed together and the mixture was freeze-dried. The liposomes were regenerated by adding distilled water, followed by shaking with a Vortex mixer (FD method). Electron microscopic observation revealed that the liposomes prepared by this method have a multilamellar structure. The liposomes had approximately eight times as much encapsulating ability as those prepared by the ordinary thin film method.