Development and validation of visible spectrophotometric method for determination of ferrous bisglycinate in bulk and formulation

This study aims to develop a simple, precise, and cost-effective visible spectrophotometric method to quantify ferrous bisglycinate in its bulk and dosage form. Ferrous bisglycinate, an iron chelate used in dietary supplements and food fortification, treats iron deficiency anemia with fewer side effects than other iron formulations. Despite numerous analytical methods available for iron analysis, no visible spectrophotometric techniques have been reported for ferrous bisglycinate. The method was validated according to ICH Q2 (R1) guidelines. The method development involved determining the wavelength of maximum absorption (λmax) at 510 nm. A linear calibration curve was established for ferrous bisglycinate in the concentration range of 1.0–5.0 µg/ml, with a high correlation coefficient (r2 = 0.9943). The method demonstrated high accuracy, with recovery rates between 98.54 and 99.98%, and precision, with %RSD values below 2% for intra-day and inter-day studies. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.42 µg/ml and 0.60 µg/ml, respectively, indicating high sensitivity. Repeatability and ruggedness studies confirmed the method’s reliability and consistency across different analysts and experimental conditions. The method was successfully applied to the analysis of ferrous bisglycinate in marketed tablets, with results showing a % assay between 98.24 and 100.43%. Overall, this validated visible spectrophotometric method offers a reliable and efficient approach for the quantitative analysis of ferrous bisglycinate in bulk and pharmaceutical formulations.