Spectrophotometric Determination of Iron (III) in Anti-Anemia Drugs and Biological Evaluation of HMNTDABA as an Anticancer Agent

A sensitive and accurate spectrophotometric method was developed for the determination of iron (III) using the azo reagent 2-hydroxy-5-(5-(4-methoxy-3-nitrophenyl)-1,3,4-thiadiazol-2-yl) diazenyl) benzoic acid (HMNTDABA). The reagent was prepared and characterized using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), 1H-NMR spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and elemental analysis (CHNS). The complexation reaction between HMNTDABA and Fe(III) proceeds instantaneously at an optimal wavelength of 485 nm and pH 3.5, yielding a stable yellow complex with a detection limit of 0.104 ppm. The proposed method exhibited excellent precision (S.D. = 0.0012, R.S.D. = 0.17%) and a recovery rate of 97.36%. The stability constant for the 1:2 metal-to-reagent complex was calculated to be 15 × 108 L2.mol−2, with linearity observed across the concentration range of 1–40 ppm. Additionally, the biological activity of HMNTDABA was evaluated against MCF-7 breast cancer cells, revealing concentration-dependent cytotoxic effects and characteristic apoptotic morphological changes. The proposed spectrophotometric method was successfully applied for the quantitative determination of iron(III) in commercial pharmaceutical formulations, including Ferro Strong syrup and Supervit tablets, with results comparable to those obtained by atomic absorption spectroscopy.