Absorption, excretion, and utilization of an intramuscular iron-poly (sorbitol-gluconic acid) complex, Ferastral

An iron-poly (sorbitol-gluconic acid) complex (Ferastral) labelled with 59Fe was administered by intramuscular injection to clinically and haematologically normal male volunteers. Urinary excretion of radioactivity was measured for the first 48 hours following injection, and was 2%-10% of the administered dose. Disappearance of radioactivity at the site of injection and accumulation of radioactivity in the liver, spleen, and sacrum were measured by external scintillation counting. Plasma radioactivity was measured at intervals for four days and red cell incorporation of 59Fe reached levels of 29%-57.5%. An unexpected finding was that the highest levels of urinary excretion of radioactivity did not coincide with the highest levels of plasma radioactivity.