Unexplored Role of HPTLC and HPLC in Greener Quantification of Metformin and Vildagliptin: A Critical Review

Metformin and vildagliptin are widely prescribed antidiabetic agents used in fixed-dose combinations to improve glycemic control in type 2 diabetes mellitus. High-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) are well-established techniques for their simultaneous quantification in pharmaceutical formulations. However, conventional methods often rely on hazardous organic solvents and generate significant chemical waste, posing environmental and health concerns. This review critically evaluates the unexplored potential of greener HPLC and HPTLC methods for metformin and vildagliptin quantification, emphasizing green analytical chemistry principles such as solvent reduction, eco-friendly mobile phases, and energy-efficient procedures. Fifteen recent studies are analyzed for their greenness metrics, including Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), and AGREE assessments. Current gaps in method development, especially in HPTLC greening, are identified, and future directions towards sustainable chromatographic assays are proposed. This review aims to guide researchers in developing environmentally responsible, sensitive, and reliable analytical methods for quality control of antidiabetic combinations