Quality and In Vivo Assessment of a Fulvic Acid Complex: A Validation Study

Abstract

The present work aimed to re-assess the bioavailability enhancement potential of fulvic acid (FA). Carbamazepine (CBZ) and peat were used as a model drug and FA source, respectively. Our group has already evaluated the bioavailability enhancement potential of a less commercially viable source of FA, i.e., shilajit. In the present work, the phase solubility of CBZ was analyzed with varying concentrations of peat-sourced FA (2–12% w/v). The prepared complex (CBZ-FA) was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Dissolution, pharmacokinetic, and pharmacodynamic studies were also carried out. The results showed the presence of an interaction between the drug and FA within the complex, which led to 98.99 ± 2.0% enhancement in drug solubility. The results also showed 79.23 ± 2.1% dissolution of the complexed drug over 60 min and 69.32 ± 2.2% permeation from the intestinal gut sac over 90 min, which led to a significant enhancement of bioavailability and a reduction in the duration of epileptic seizures. Thus, this study re-authenticates our earlier results and suggests switching the FA source (shilajit to peat) for commercial product development.