Comparison of Microdialysis and Ultrafiltration Methods for Determination of Plasma Protein Binding Rate of Polydatin in Vitro

OBJECTIVE The microdialysis method was used to study the plasma protein binding rate of polydatin, and the obtained results were compared with those of the conventional ultrafiltration method. METHODS The microdialysis- HPLC method was applied to dialysis the difference of concentration between dialysis fluid and perfusion fluid concentration on linear regression analysis, so the concentration of free polydatin in drug-containing plasma could be calculated, then the binding rate of polydatin with rat and human plasma can be calculated, and compared with ultrafiltration method. RESULTS The plasma protein binding rate of polydatin of rat and human plasma were about 86.15% and 89.08% respectively for microdialysis method, and were around 86.15% and 89.08% for ultrafiltration method. There was no significant difference between the two methods. CONCLUSION The binding percentage of polydatin with rat and human plasma is relative high, and results of the two methods are consistent.