Determination of antihypertensive drugs irbesartan and doxazosin mesylate in healthcare products and urine samples using surface-enhanced Raman scattering

In this paper, a surface-enhanced Raman scattering (SERS) strategy was constructed for the determination of antihypertensive drugs irbesartan (IRB) and doxazosin mesylate (DOX). beta-Cyclodextrin-capped silver nanoparticles (CD-AgNPs) are employed as SERS-active substrate. The introduction of beta-CD with hydrophobic cavity can capture drug molecules to form host-guest complex, making the drug molecules closer to the electromagnetic enhancement field of the AgNPs, thereby enhancing the SERS signal of drug molecules with low Raman cross-section. The vibrational modes of IRB and DOX are assigned by density functional theory calculations. The linear response from 3.0 x 10(-7) to 1.0 x 10(-5) mol L-1 for IRB and 3.0 x 10(-7) to 2.0 x 10(-5) mol L-1 for DOX and low limits of detection (LOD) 7.5 x 10(-8) mol L-1 for IRB and 8.6 x 10(-8) mol L-1 for DOX can be achieved. Meanwhile, this SERS approach can be applicable to determine IRB and DOX in commercial drug tablets, healthcare products, and human urine samples with recoveries of 90.8-115.7% and 90.0-113.5%, respectively, with relative standard deviation (RSD) less than 4.5%. This designed SERS strategy enables for the rapid determination of IRB and DOX in drug quality monitoring and illegal additives in healthcare products as well as clinical applications.