Stable microcrystalline cisplatin

Stable microcrystalline cisplatin (I) having a particle size distribution of at least 80% in the range of 0-5 micrometres, less than 20% of 5-20 micrometres and none larger than 20 micrometres is new. The microcrystalline (I) is different from lyophilised (I), as shown by X-ray powder diffraction paterns. The microcrystalline (I) is soluble in water within 3 mins. at 1 mg/ml. The stability and good water solubility of the microcrystalline (I) are useful when it is used in sterile unit dosage forms (also contg. an inorganic chloride to provide Cl ions); these forms can be stored at room temp. and are easily reconstituted with sterile water to give parenteral prepns. The (I) is used for concer chemotherapy in the usual way.