Physicochemical Properties and Lipophilicity of Polydatin- Lecithin Complex

Purpose: To investigate the physicochemical properties and lipophilicity of polydatin-lecithin complex.
Methods: The complex of polydatin-lecithin was prepared by solvent method. The physicochemical properties of the complex were investigated by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), differential scanning calorimetry (DSC), x-ray diffractometry (XRD) and scanning electron microscopy (SEM). Its solubility in n-octanol at 25 °C was examined by high performance liquid chromatography (HPLC).
Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which the characteristic absorption of their respective peaks were retained. DSC and XRD results suggest that the complex mainly showed the presence of lecithin with the characteristic peaks for polydatin absent, while SEM demonstrated that polydatin was dispersed in lecithin. HPLC analysis found that the solubility of polydatin in n-octanol at 25 °C was enhanced from 0.41 mg/mL to 21.98 mg/mL by complexing with lecithin, indicating that the lipophilicity of polydatin was significantly improved.
Conclusion: Polydatin and lecithin in the complex are combined by non-covalent bonds, and did not form a new compound. The lipophilicity of polydatin increased to 21.98 mg/mL from 0.41 mg/mL as a result of complexation.