Specific hybrid liposomes composed of phosphatidylcholine and polyoxyethylenealkyl ether with markedly enhanced inhibitory effects on the growth of tumor cells in vitro.

The hybrid liposomes (90mol% DMPC/10mol% C12(EO)8 and 90mol% DMPC/10mol% C12(EO)12) have a highly inhibitory action against the growth of tumor cells. The uniform and stable structure of the hybrid liposomes was revealed on the basis of electron microscopy and dynamic light scattering measurements.