DEVELOPMENT OF A MELANIN-BASED HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY STATIONARY-PHASE AND ITS USE IN THE STUDY OF DRUG-MELANIN BINDING INTERACTIONS

Drug-melanin interactions were studied using a melanin-based HPLC column. Two approaches were chosen for the preparation of the stationary phases: covalent coupling of synthetic L-dopa melanin and in situ polymerization of L-dopa. Retention of a series of phenothiazines on melanin-based stationary phases was attributed to binding to melanin. Frontal affinity chromatography experiments on one melanin-based column allowed us to calculate the affinity and binding capacity of chlorpromazine and promethazine. A competition was observed between chlorpromazine and haloperidol which was qualitatively consistent with previously described results. Data indicated that the interaction was not a simple competition at one site. (C) 1995 Academic Press, Inc.