A liposomal formulation of the prodrug oxaliplatin, an organoplatinum complex in which the platinum atom is complexed with 1,2-diaminocyclohexane (DACH) and with an oxalate ligand as a 'leaving group', with antineoplastic activity. After displacement of the labile oxalate ligand leaving group, the active oxaliplatin derivatives monoaquo and diaquo DACH platinum alkylate macromolecules, and form both inter- and intra-strand platinum-DNA crosslinks; inhibition of DNA replication and transcription and cell-cycle nonspecific cytotoxicity ensue. The DACH side chain appears to inhibit alkylating-agent resistance. A leaving group is an atom or a group of atoms that is displaced as a stable species taking with it its bonding electrons.