[Ciprofibrate: erythrocyte partition coefficient and binding to serum protein]

The in vitro binding of the lipid lowering agent Ciprofibrat (1) to different plasma protein fractions and its red blood-cell partition coefficient were investigated. The binding-rate to albumin and alpha-globulin is dose-dependent (first order kinetic) and amounts to about 95% for albumin and to 25% for alpha-globulin. The affinity of 1 to beta- and gamma-globulin is non-specific and dose-independent (average binding-rate 8% and 10%, respectively). 1 shows only a weak affinity to erythrocytes, therefore, the red blood-cell partition coefficient is 0.02.