Simultaneous determination of 5 diuretic drugs using a HPLC method by quantitative analysis of multi-components by single-marker

Background: Loop diuretics is commonly used in clinical practices to manage the high fluid load and to control fluid balance. In this paper, a quantitative analysis of multiple components with a single marker (QAMS) method was firstly developed for simultaneous determination of 5 diuretic drugs including furosemide, torasemide, azosemide, etacrynic acid, and bumetanide by HPLC. The qualitative analysis was performed using relative capacity factor and ultraviolet (UV) spectral similarity as the double indicator. The QAMS method was conducted with etacrynic acid as an internal reference substance. The other four diuretics were calculated by using the relative correction factors for etacrynic acid. The contents of the 5 diuretic drugs were also determined by the external standard method (ESM). The chromatographic separation was achieved on an Shimadzu HC-C18 column (150mm× 4.6mm, 5µm) using 50 mM of potassium dihydrogen phosphate (pH adjusted to 4.0 with phosphoric acid) with acetonitrile (64:36, v/v) as mobile phase at the flow rate of 1.0 ml/min and a column temperature of 30℃. Results: Under these conditions, the 5 diuretic drugs are well separated, showing linear relationships within certain ranges. The quantitative results showed that there was no significant difference between the QAMS and ESM method. Conclusions: Overall, the HPLC-QAMS analytical scheme established in this study should be a simple, efficient, economical, and accurate method for quantitative evaluation of 5 diuretic drugs.