A high‐performance liquid chromatography method for simultaneous quantification of metformin and ferulic acid in solid dosage forms

Metformin is one of the most commonly used drugs in the world for the treatment of type 2 diabetes, while ferulic acid is a molecule that stands out for its antioxidant potential. Recent studies demonstrate hypoglycemic synergy between these molecules. The objective of this study is to develop and validate an analytical methodology by high‐performance liquid chromatography for the simultaneous quantification of these drugs in pharmaceutical formulations. The method used an octadecylsilane column and a mobile phase composed of 6 mM sodium lauryl sulfate in 15 mM phosphate buffer:ACN (65:35). Ferulic acid and metformin were monitored at 232 nm, with a mobile phase flow rate of 1 ml/min and oven temperature at 40°C. The method was linear in the range of 5–25 μg/ml for both molecules. In the presence of degradation products, satisfactory selectivity was achieved. Accuracy values were close to 100% and standard deviations in precision were less than 2%. In the robustness evaluation, the proposed variations did not interfere with the quantification. Therefore, it is concluded that the present method can be safely applied to the quality control of ferulic acid and metformin raw materials, as well as when they are combined in pharmaceutical formulations.