摘要:
This study investigates the solubility of baicalein (Ba) with the addition of modified cyclodextrins using phase solubility method. The solubility of Ba in the presence of natural (alpha-,beta-, and gamma-) cyclodextrins and its derivatives, namely, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and (2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD), was higher than that of free Ba. In particular, the stability constant of inclusion complex with DM-beta-CD was 13672.671 mol(-1), which was the highest among the examined cyclodextrins. The inclusion complexes of Ba and DM-beta-CD were prepared via freeze-drying method, which were both characterized in the solution and solid state by UV-vis spectroscopy, differential scanning calorimetry (DSC), proton nuclear magnetic resonance (H-1 NMR), scanning electron microscopy (SEM), and X-ray powder diffractometry (XRPD). The UV-vis, DSC, H-1 NMR, SEM, and XRPD results proved the formation of inclusion complex between Ba and DM-beta-CD. Furthermore, the dissolution rate and thermal stability of the inclusion complex were significantly enhanced compared with the pure drug. Therefore, using DM-beta-CD can effectively improve the solubility and thermal stability of free Ba, which is a promising approach to promote its clinical application. (C) 2013 Elsevier Ltd. All rights reserved.