Determination of free iron content in pharmaceutical products containing different iron complexes by using polarography method: "Method development and validation study".

Iron carbohydrate complexes such as iron gluconate, iron sucrose, ferric carboxy-maltose, iron isomaltoside, ferumoxytol, and iron dextrans, which have been used in the treatment of iron deficiency anemia for many years, release excess iron into the circulation and produce free iron, which leads to oxidative stress and tissue damage. Therefore, the determination of free iron and keeping it within acceptable limits in pharmaceutical products is vital in product quality and patient safety. For this purpose, in the presented study, an alternative methodology is discussed for the determination of free iron in various pharmaceutical iron complexes (iron(III)-sucrose, iron(III)‑hydroxy polymaltose, and iron(III)-carboxymaltose), different from the normal pulse polarography(NPP) technique reported in the United States Pharmacopoeia (USP) for iron(III)-sucrose. The critical steps such as the selection process of parameters and analytical conditions and the accuracy of the obtained results for the polarography-based analytical method optimization of different pharmaceutical forms are examined by utilizing differential pulse polarography (DPP), which has advantages such as high sensitivity, reproducibility, and detection limits in the determination of different valence ions compared to classical methods. Thus, we aim to shed light on validation processes for the direct determination of free iron in various pharmaceutical formulations, expand the existing literature on the subject, and contribute to quality control processes in the pharmaceutical industry.