A low toxicity, stable oxazaphosphorine containing compositions with mesna forparenteral administration has been described. The process essentially requiresaddition of an oxazaphosphorine antineoplastic to the aqueous solution of anetherified b-cyclodextrin followed by addition of mesna as such or as anaqueous solution containing optionally, an etherified b-cyclodextrin.Preferably, the oxazaphosphorine antineoplastic is Ifosfamide and theetherified b-cyclodextrin is 2-hydroxypropyl-b-cyclodextrin.
