EFFECT OF CERTAIN FACTORS ON BINDING OF KETOPROFEN TO HUMAN SERUM ALBUMIN

A study was made to investigate the interaction of Ketoprofen with human serum albumin (HSA) in isotonic Sorensen's phosphate buffer of pH 7.4 at 37°C. The equilibrium dialysis technique was used to assess factors influencing Ketoprofen binding to HSA. Results have demonstrated a marked binding of Ketoprofen to HSA. The binding characteristics were affected by certain factors. Increasing the concentration of the drug was accompanied by a reduction in the amount bound to HSA. While, binding of the drug with HSA was directly proportional to HSA concentration. Changing pH values had no effect on the binding of drug with HSA. Addition of three organic aliphatic acids, namely citric, tartaric and acetic acid to (HSA) did not result in significant changes in the values of binding parameters of drug to HSA, In contrast, the addition of succinic acid to albumin-Ketoprofen solution resulted in a decrease in the binding of drug to albumin. The addition of relatively large amounts of creatinine, uric acid and phenol failed to produce a significant decrease in Ketoprofen binding. In contrast, it has been found that urea more or less decreased Ketoprofen Binding and this decrease was concentration dependent. Regarding the effect of guanidines on the binding of Ketoprofen to HSA, it was found that both methylguanidine, guanidinosuccinic acid guanidinoacetic acid failed to induce a significant changes in values of binding parameters. The binding of Ketoprofen to HSA was examined in presence of four indolic compounds namely; indole-acetic acid, indican, indole-lactic acid and indole butyric acid. It was found that, all indolic compounds showed a significant decrease in Ketoprofen albumin binding and this decrease was concentration dependent. The order of inhibitory capacity was indole- lactic acid < indican < indole-acetic acid < indole-butyric acid.