Enhanced hepatoprotective activity of andrographolide complexed with a biomaterial

Context: Humic acid (HA), a natural organic matter is recently being investigated for pharmaceutical purposes. Andrographolide (AGP), a potent hepatoprotective, possesses low aqueous solubility which results in a low bioavailability after oral administration, inappropriate tissue localization and consequently poor therapeutic application. Objective: The present study investigates the complexation of AGP with HA to increase its solubility and hepatoprotective efficacy. Materials and methods: Complexes prepared by solvent evaporation in various weight ratios were characterized using differential scanning calorimetry, Fourier Transform InfraRed spectroscopy, X-ray diffraction, and scanning electron microscopy. Results and discussion: The complexed AGP demonstrated improved solubility, dissolution, and permeation across rat intestine. It also displayed better hepatoprotection against carbontetrachloride- induced liver toxicity than the free drug in rats. Conclusion: Complexation with HA is a valuable technique to improve solubility and bioavailability of pharmaceuticals.