A sterile composition comprising a isophosphoramide mustard compound of structural formula shown herein is disclosed, wherein X and Y independently represent leaving groups, or a pharmaceutically acceptable salt thereof； and wherein the compound is present with less than 10% decomposition products relative to the compound itself. A method of purifying a salt of said isophosphoramide mustard compound is also disclosed, wherein the method comprises filtering a solution of the compound through a sterile antimicrobial filter, whereby the purified compound undergoes less than 10% decomposition during filtration. These sterile compositions are suitable for treatiing hyperproliferative disorder selected from breast cancer, bladder cancer, bone cancer, cervical cancer, colon cancer, central nervous system cancer, esophageal cancer, gall bladder cancer, gastrointestinal cancer, head and neck cancer, Hodgkin's Disease, non-Hodgkin's lymphomas, laryngeal cancer, leukemia, lung cancer, melanoma, neuroblastoma, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, renal cancer, retinoblastoma, stomach cancer, testicular cancer and Wilms tumor.
