Iron deficiency is a common complication in chronic kidney disease (CKD), driven by blood loss, reduced intestinal iron absorption, depleted iron stores, chronic inflammation, and elevated hepcidin levels, leading to both absolute and functional iron deficiency. Intravenous ferric carboxymaltose (FCM) provides faster and more reliable iron repletion than oral iron, particularly when absorption is impaired. The physicochemical characteristics of FCM, especially carbohydrate content and Critical Biological Product (CBP*) parameters, are essential for formulation stability, controlled iron release, and clinical performance. Variability among FCM formulations may influence iron release, efficacy, long-term safety, and bioequivalence. Therefore, careful evaluation of CBP parameters is important when selecting an FCM formulation to optimize safety and therapeutic outcomes in patients with CKD-related iron deficiency anemia.^[1][2]