Abstract: The present invention provides a W/O/W multiple emulsion composition composed of an internal aqueous phase, an oil phase, and an external aqueous phase, the internal aqueous phase containing an ionic physiologically active substance and a physiologically acceptable compound having a molecular weight of 1,000 or less and generating a polyvalent counterion with two or more valencies for the ionic physiologically active substance. The W/O/W emulsion composition of the present invention not only can stably encapsulate a useful substance in its internal aqueous phase at a high encapsulation ratio, but also has high safety.

Abstract: A method for efficiently transferring a gene to a target cell is provided. A method of transferring a gene to a target cell, including adding or administering a positively charged complex (A) composed of the gene and a cationic substance and gas-filled microparticles (B) to a target cell-containing composition or a living body and then exposing the target cell-containing composition or the living body to a low-frequency ultrasound.

Abstract: Gas-filled liposomes that are useful for ultrasonography and ultrasound therapy are provided. A method of producing the gas-filled liposomes, including filling the void space in a sealed container containing a liposome suspension in a volume amounting to 20 to 80% of the inner capacity thereof with a fluoride gas or a nitrogen gas, and subjecting the container to an ultrasonication.

Abstract: The present invention provides a liposome preparation containing oxaliplatin and derivatized with a hydrophilic polymer and a ligand. In one embodiment the hydrophilic polymer is polyethylene glycol and the ligand is transferrin. In accordance with the invention, the uptake of a pharmaceutical agent contained in the liposome into tumor cells can be enhanced through transferrin receptors expressed on the surface of the tumor cells. Also provided are pharmaceutical compositions containing the liposomes and methods of their use.

Abstract: The present invention provides a liposome preparation containing oxaliplatin and derivatized with a hydrophilic polymer, as well as a pharmaceutical composition for treatment of tumor comprising the liposome preparation. The liposome preparation according to the present invention is characterized in that it is derivatized with a ligand. The ligand is preferably transferrin. In accordance with the invention, the uptake of a pharmaceutical agent in the liposome into tumor cells can be enhanced through transferrin receptors expressed on the surface of the tumor cells.