Abstract
In this study, a highly sensitive enzyme-linked immunosorbent assay (ELISA) has been developed and validated for the determination of rosuvastatin (ROS) in plasma samples at picogram level. The assay employed a polyclonal antibody that specifically recognizes ROS with high affinity, and ROS conjugate of bovine serum albumin (ROSBSA) immobilized onto microplate wells as a solid phase. The assay involved a competitive binding reaction between ROS, in plasma sample, and the immobilized ROS-BSA for the binding sites on a limited amount of the anti-ROS antibody. The bound anti-ROS antibody was quantified with horseradish peroxidase-labelled second anti-rabbit IgG antibody (HRP-IgG) and 3,3`,5,5`-tetramethylbenzidine (TMB) as a substrate for the peroxidase enzyme. The concentration of ROS in the sample was quantified by its ability to inhibit the binding of the anti-ROS antibody to the immobilized ROS-BSA and subsequently the colour intensity in the assay wells. The assay limit of detection was 25pgml1 and the effective working range at relative standard deviations (RSD) of 5% was 402000pgml1. Analytical recovery of ROS from spiked plasma was 96.2 104.8 +/- 2.12 5.42%. The precision of the assay was satisfactory; RSD was 2.47 4.46 and 3.24 5.27% for the intra- and inter-assay precision, respectively. The analytical procedure is convenient, and one can analyze similar to 200 samples per working day, facilitating the processing of large-number batch of samples. The proposed ELISA has a great value in routine analysis of ROS for its pharmacokinetic studies. Copyright (c) 2011 John Wiley & Sons, Ltd.