Protein Binding Study of S-ibuprofen Using HPFA Analysis

초록

High performance frontal analysis (HPFA) was used for the determination of binding constant of S ibuprofen to human serum albumin (HSA). The HPFA system was consisted of an inertsil HPLC column (100 Diol 5, 4.6 * 100 mm) and sodium phosphate buffer (pH 7.4 and ionic strength of 0.17) as the mobile phase of. The flow rate of the mobile phase was 1ml/min and the UV wavelength was set at 220nm. Sample mixtures of S ibuprofen and HSA (70 uM) were directly injected into the HPFA column, S ibuprofen was eluted as a zonal peak containing a plateau region after HSA. An injection volume of 200 ul and a “restricted injection” method were applied to ensure the solute eluted formed a zonal peak with a plateau. The drug concentration in the plateau region is the same as that of the unbound drug concentration in the sample solution. Therefore, the unbound drug concentration was calculated from the peak height of the zonal peak. By Scatchard analysis, the binding constant (K) and binding affinity (nK) of S ibuprofen to HSA were 2.833 * 104 [1/M], 4.935 * 104 [1/M], respectively.