An analytical method for Fe(II) and Fe(III) determination in pharmaceutical grade iron sucrose complex and sodium ferric gluconate complex

A robust voltammetric method has been developed and validated for the determination of Fe(II) and Fe(III) in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe(II) and Fe(III) composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.