Simultaneous determination of some illegal antihypertensive and diuretic drugs in traditional herbal preparations by HPLC-DAD

Abstract

A simple, stable, and specific high-performance liquid chromatography coupled with a DAD detector (HPLC-DAD) method has been developed and validated for the simultaneous determination of amlodipine, felodipine, furosemide, nifedipine, and spironolactone in traditional herbal products. The analytes were extracted in acetonitrile: water (50 : 50, v/v) with help of the ultrasonic. The separation of analytes was performed in an Apollo C18 column (250 × 4.6 mm; 5 μm) and a mobile phase consisting of mixture acetonitrile: 0.1% phosphoric acid in gradient elution. The analyzed drugs were detected at 238 nm. The method was validated according to the AOAC International guidelines concerning specificity, linearity, precision (repeatability, intermediate precision), accuracy, limit of detection (LOD), and limit of quantification (LOQ). The method can detect the studied drugs at the concentration of 0.66 to 1.25 μg/g for dry samples and 0.10 to 0.24 μg/mL for liquid samples. The method was successfully applied in the analysis of 17 samples in the local market. No samples were found positive for the substances to be analyzed.