A Metformin-Ferulic Acid Salt with Improved Biopharmaceutical Parameters

Though ferulic acid presents great hypoglycemic potential, it possesses limited aqueous solubility, and low oral bioavailability. When associated with metformin, the first-choice drug in Type 2 diabetes treatment, FA demonstrates synergistic hypoglycemic effects, however, it also causes certain undesirable dose-related effects. This study aimed to develop a new ferulic acid - metformin multicomponent system, and incorporate it into a solid dosage form with improved biopharmaceutical parameters. A novel metformin: ferulate (1:1) salt (MFS) was produced, which was properly characterized using differing analytical techniques, including single crystal analysis. Also during the course of the study, a new polymorph of the metformin free base was observed. The MFS was obtained using solvent evaporation methods, which achieved high yields in reproducible process, as well as a 740-fold increase in ferulic acid aqueous solubility. The MFS tablets developed met quality control requirements for this dosage form, as well as revealing excellent performance in vitro dissolution tests, presenting dissolution efficiency values of 95.4 ± 0.5%. Additionally, physicochemical instability was not observed in a study at 40 °C for 3 months for both MFS powder and its tablet form. The MFS product developed is a promising candidate for further Type 2 diabetes clinical study.