Development of a method for evaluating the entrapment efficiency in the formulation of andrographolide phytosome

Abstract

Objective: This study aimed to develop a method for evaluating the entrapment efficiency of AG in the formulation of AG-P. Methods: The andrographolide phytosome was prepared using the solvent evaporation technique. An approach using the selective dissolution solvent was employed to remove free AG. Key parameters, including solvent type and sonication time, were optimized to enhance selective dissolution efficiency of AG in AG-P form. The interaction and complexation between AG and PC of andrographolide phytosome were confirmed by FT-IR, ¹H-NMR, XRD, and DSC measurement. Results: Benzene was selected as a selective dissolution solvent for AG in phytosome form, exhibiting minimal solubility for the free form of AG. The optimal sonication time for the phytosome in the selective solvent was determined to be 60 minutes. Under these conditions, the solubility of andrographolide in phytosome form was 1495.18±24.66 mg/ml, which was significantly higher in many folds than that of free andrographolide (19.83±0.07 mg/ml). Data of FT-IR, ¹H-NMR, XRD and DSC measurement confirmed the formation of complex between AG and phosphatidylcholine in AG-P. Conclusion: A method for evaluating the entrapment efficiency of AG in the formulation of AG-P was successfully developed. This method is simple, easy to perform and plays a significant role in the formulation and production of andrographolide phytosomebased pharmaceutical products.