Studies on interaction between drugs with serum albumin by modified fluorescence spectroscopy

To resolve the deficiencies in the interaction analysis by classical fluorescence spectroscopy between serum albumin (SA) and drug, a modified fluorescence spectroscopy has been applied to study the binding constant (K,,) of the interaction between SA and primaquine, sodium dodecyl benzene sulfortate and citalopram under simulated physiological conditions ( pH = 7.4 in which the fluorescence detective object is small molecule drugs and the quencher is SA. The values of K-b obtained were 8.16 x 10(4) L/mol, 4.14 x 10(6) L/mol and 6.08 x 10(7) L/mol, respectively. The rationality and correctness in the modified method has been proved based on Ultra-Violet absorption spectroscopy. The results show that this modified method can reveal the more and true information of some interactions. Thus the interaction mode between drugs and SA included point-to-area has been drawn.