DRUG ACCUMULATION IN MELANIN - AN AFFINITY CHROMATOGRAPHIC STUDY

The affinity of several drugs to melanin has been indirectly assessed using an affinity chromatographic approach based on immobilized melani n. Plots of the retention of the drugs on the affinity column versus t he number of molecules applied were fitted best by nonlinear, exponent ial curves characteristic for each drug. These curves reflect the comp lexity of the binding behaviour, consisting of a variety of hydrogen b onding, hydrophobic or ionic interactions as well as cooperative or an ti-cooperative interactions between the drug molecules and melanin. Th e nonlinear fitting procedure was based on a descriptive function and allowed to discriminate the binding behaviour according to parameter e stimates which specified the investigated drugs. (C) 1998 Elsevier Sci ence B.V. All rights reserved.