The study of the bio-recognition phenomena behind biological processes is nowadays considered a useful tool to understand physiological mechanisms, discover novel biological targets, develop new lead candidates and characterize the ADMET properties of new drugs. Monitoring drug binding to plasma proteins is becoming essential to characterize the drug distribution in human body; in particular the study of binding mechanisms to human serum albumin is crucial to the early characterization of the pharmacokinetic profile of new potential leads. Furthermore, most of the distribution experiments carried out in vivo are performed on animals. Hence, it is interesting to determine the binding of new compounds to albumins from different species in order to evaluate the reliability of extrapolating the distribution data obtained in animals to humans. In this work, three different biochemical techniques have been applied to this purpose: high performance liquid affinity chromatography, circular dichroism and optical biosensor.