Binding of trazodone hydrochloride with human serum albumin: A spectroscopic study

The binding of trazodone hydrochloride (TZH) to human serum albumin (HSA) was investigated by spectroscopic techniques. Various binding parameters have been evaluated. Negative enthalpy and positive entropy values indicated that both hydrogen bond and hydrophobic forces played a major role in the binding of TZH to HSA. The distance, r between donor (HSA) and acceptor (TZH) was found to be 2.16 nm based on the Foster's theory of non-radiation energy transfer. The circular dichroism data indicated that the alpha-helicity of HSA decreased upon interaction with TZH. The binding constant of HSA-TZH was found to decrease in presence of common ions and hence, shortened the stored time of drug in blood plasma. (c) 2006 Elsevier B.V. All rights reserved.