A Simple and New HPLC Technique for the Determination of Monothioglycerol, an Antioxidant, in Raw Materials and Parenteral Preparations: Assessment of Greenness, Blueness, and Whiteness Scores

Monothioglycerol predominantly acts as an antioxidant in injectable solutions, inhibiting the oxidation and degradation of medications that are sensitive to oxygen, alongside other formulation ingredients. It scavenges free radicals and ceases the chemical chain reactions that result in instability. A thorough, swift, straightforward, and eco-friendly stability-indicating liquid chromatography (LC) method has been developed and validated, facilitating the measurement of monothioglycerol concentrations in injectable solutions. The antioxidant was studied through several tests in accordance with ICH guidelines, including characteristics such as forced degradation studies. Through isocratic separation, monothioglycerol and its related degradants were effectively resolved. The antioxidant was determined using an end-capped octadecylsilyl (C18) column, and the method was validated under room temperature conditions. The isocratic mobile phase operates at a flow rate of 1.0 mL/min and consists of fixed ratios of filtered water, acetonitrile, and orthophosphoric acid. The overall AES grade of 86, AGREE grade of 0.64, MoGAPI grade of 76, BAGI grade of 75.0, and ultimate whiteness of 95.8 all highlight the ecological advantages of the HPLC method. The current research indicates that the proposed methodology is unique, precise, accurate, stable, and environmentally beneficial at a microscale, making it suitable for routine quality control analysis.