Quantitative analysis of human serum albumin–drug interactions using reversed-phase and ion-exchange liquid chromatography Original Research Article

A new liquid chromatographic system was developed to measure protein-drug binding affinity indirectly and evaluated using log nK values of acidic drugs measured by a modified Hummer–Dryer method using purified human serum albumin. The retention factors of acidic drugs were measured in two reversed-phases and an ion-exchange liquid chromatography. The bonded phases were butyl, phenylpropyl and guanidino phases, and their retention factors were measured in sodium phosphate buffer of pH 7.5. The combined retention factors were correlated with the measured log nK values; the correlation coefficient was 0.948.