alexa Determination of simvastatin-derived HMG-CoA reductase inhibitors in biomatrices using an automated enzyme inhibition assay with radioactivity detection.
Chemistry

Chemistry

Medicinal Chemistry

Author(s): Liu L, Zhang R, Zhao JJ, Rogers JD, Hsieh JY,

Abstract Share this page

Abstract A robust, automated enzyme inhibition assay method was developed and validated for the determination of HMG-CoA reductase inhibitory activities in plasma and urine samples following simvastatin (SV) administration. The assay was performed on Tecan Genesis 150 and 200 systems equipped with 8-probe and 96-well plates. Plasma samples containing HMG-CoA reductase inhibitors were treated with acetonitrile for protein precipitation before being incubated with HMG-CoA reductase, [14C]-HMG-CoA, and NADPH for a fixed length of time at a fixed temperature. The product, [14C]-mevalonic acid, was lactonized and separated from excess substrate via a small ion exchange resin column, and radioactivity was counted on a scintillation counter. HMG-CoA reductase inhibitors were measured before and after base hydrolysis. The two values obtained for each sample are referred to as 'active' and 'total' HMG-CoA reductase inhibitor concentrations. Simvastatin acid (SVA), the beta-hydroxy acid of SV, was used as a standard to generate a calibration curve of HMG-CoA reductase activity versus SVA concentration (ng/ml). Three calibration ranges, 0.4-20, 2-50, and 50, 100 ng/ml, in human and animal plasma and urine were validated. The assay precision was less than 8.5\%, CV in plasma and less than 10.4\% in urine. The assay accuracy was 93.6-103.0 and 98.1-103.9\% for the 0.4 20 and 2-50 ng/ml calibration ranges, respectively, in human plasma, and was 97.3-105.1, 94.4- 105.2, and 90.2-95.7\%, for calibration range 5-100 ng/ml in rat plasma, dog plasma and human urine, respectively.
This article was published in J Pharm Biomed Anal and referenced in Medicinal Chemistry

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords