Oncological study in rats of Ferastral, an iron-poly-(sorbitol-gluconic acid) complex, after intramuscular...

Four groups of Sprague-Dawley rats were given Ferastral, an iron-poly(sorbitol-gluconic acid) complex (IPSG) or Imferon, an iron-dextran complex, intramuscularly twice a week for 17 weeks. The experiment lasted for 95 weeks. Each compound was given to two groups, one low dose group and one high dose group. Depending on the body mass, the dose levels varied between 2.5 and 10 mg (25-50 mg/kg body mass) and between 5 and 20 mg (50-100 mg/kg body mass) of iron per rat, respectively. The mean total dose of iron per rat was calculated to be 235 and 495 mg, respectively. Another group of animals served as a control. From about the 30th experimental week onwards tumours developed at the intramuscular injection sites in the groups given Ferastral and Imferon. The tumours appeared to be sarcomas. In almost all the treated animals that lived longer than 30 weeks after the start of the experiment, sarcomas were present at the intramuscular injection sites. The sarcomas appeared earlier in the high dose groups than in the low dose groups and slightly earlier in the rats given Ferastral than in those given Imferon. No other pathological changes, including neoplasms, were considered to be related to the treatment.