EFFECT OF CHLORPHENIRAMINE MALEATE ON BINDING CAFFEINE TO HUMAN SERUM-ALBUMIN

The effect of Chlorpheniramine maleate (CFAM) on the binding of Caffeine to humman serum albumin (HSA) were examined using fluorescence quenching method. Three concentrations of this drug were employed: 0.1 mM, 0.01 mM and 0.001 mM. By calculating binding constant nonlineal regression method were used. Three effects were observed: a) the binding constant KI is increased with antihistaminic concentration, b) the binding constant K2 is decreased with antihistaminic concentration and c) the amount of caffeine unbound are afected by the presence of CFAM. In addition to this Lineweaver-Burk plots suggest that CFAM inhibit competitively the binding of Caffeine to HSA.