ABSTRACT
Objective To prepare a co-amorphous complex of piperine (PIP) and triterpenoids from Ligustri Lucidi Fructus (TLLF) to improve the dissolution of TLLF. Methods TLLF-PIP co-amorphous complex was prepared using solvent evaporation method. The microscopic structure of co-amorphous complex (CAC) was analyzed using differential scanning calorimetry (DSC), scanning electronmicroscopy (SEM), and powder X-ray diffraction (PXRD), the optimal ratio of the two components was investigated through the thermal stability experiment. Ultraviolet-visible spectrophotometry (UV-Vis) and high performance liquid chromatography (HPLC) were applied to determine the amount of TLLF, PIP and the individual components, ursolic acid (UA) and oleanolic acid (OA), respectively. The interaction of the optimal CAC was analyzed by Fourier transform infrared spectroscopy (FTIR), and its solubility and dissolution behavior in vitro were also studied to evaluate the formation of the preparation. Results PXRD analysis indicated that the TLLF-PIP-CAC with a mass ratio of 1:1 exhibited a stable amorphous state, which particles presented in near-spherical shape. FTIR results indicated that there are some hydrogen interactions between the moleculars of TLLF and PIP. The solubility and dissolution determination exhibited a pairwise released behavior with improved triterpenoids and decreased piperine dissolution. Conclusion The prepared TLLF-PIP-CAC can significantly improve the dissolution and amorphous stability of TLLF, which may provide a reference for the compatibility of insoluble compound in traditional Chinese medicine.