Interaction studies of chiral non-steroidal anti-inflammatory drugs with HSA protein using capillary electrophoresis frontal analysis and electrokinetic chromatography

Abstract

Human Serum Albumin (HSA) predominantly found in the blood plasma proteins, acts as a carrier for many drugs. In the present work binding interactions of eight arylpropionate non-steroidal anti-inflammatory drugs (NSAIDs) were studied with Human Serum Albumin HSA using Capillary Electrophoresis (CE) under physiological conditions. The concentration of HSA was kept constant (525 μM) whereas the drug concentrations were varied between 50-300 μM in each case. The Frontal analysis (FA) and Capillary Zone Electrophoresis (CZE) modes of CE were applied together with a mathematical modelling of the experimental results with a view to obtaining pharmacokinetic properties of each drug. The binding order of the drugs to HSA were established with the three methods together with the mathematical approach. Our studies revealed the presence of more than one binding sites for some of the available drugs. Additionally, molecular docking studies were conducted to establish the binding conformations of drugs in the binding pocket of the HSA. A very good correlation between the computed binding energies (docking) and the experimental binding constants were observed throughout this study. The logK values for all eight drugs were ranging from 3.37 - 4.56 for FA, 3.16 – 4.39 for CZE, and 3.48 – 5.30 for computational studies.