Comparative serum protein binding of anthracycline derivatives

Abstract

 The binding of doxorubicin, iododoxorubicin, daunorubicin, epirubicin, pirarubicin, zorubicin, aclarubicin, and mitoxantrone to 600 μM human serum albumin and 50 μM alpha₁-acid glycoprotein was studied by ultrafiltration at 37°C and pH 7.4. Anthracycline concentrations (total and free) were determined by high-performance liquid chromatography (HPLC) with fluorometric detection. Binding to albumin (600 μM) varied from 61% (daunorubicin) to 94% (iododoxorubicin). The binding to alpha₁-acid glycoprotein (50 μM) was more variable, ranging from 31% (epirubicin) to 64% (zorubicin), and was essentially related to the hydrophobicity of the derivatives. Simulations showed that the total serum binding varied over a broad range from 71% (doxorubicin) to 96% (iododoxorubicin).