Oxaliplatin with a low content of accompanying impurities and a method for preparation thereof

A method for preparation of oxaliplatin with a low content of accompanying impurities originating from its preparation, characterized in that the oxaliplatin contains, by weight, at most 0.01% of alkali metals, at most 0.0005% of silver, and at most 0.01% of nitrates, the method comprising:

• reacting (SP-4-2)-dichloro-[(IR, 2R)-1, 2-cyclo- hexanediamine-N, N′] platinum (II) with silver nitrate, removing the solid phase, adding iodide ions, removing the solids, and reacting the aqueous solution of the corresponding diaqua complex of platinum with oxalic acid, characterized in that a suspension of (SP-4-2)-dichloro-[(IR, 2R)-1, 2-cyclohexanediamine-N, N] platinum (II) in water is treated with silver nitrate in a molar ratio of the complex to silver nitrate of 1:<2 then, after removal of the solid phase, the obtained solution is treated with quaternary ammonium iodide of the formula (R) 4NI wherein each R independently represents hydrogen atom, or aliphatic radical containing 1 to 10 carbon atoms, or cycloaliphatic radical containing 3 to 10 carbon atoms, with the proviso that at least one of the symbols R does not represent hydrogen atom, the separated solid phase is removed and the obtained solution is treated with oxalic acid, and the separated oxaliplatin is isolated, washed with water and a polar organic solvent or their mixture, dried, recrystallised from water, washed with water and polar organic solvent or their mixture, and dried.