Rapid HPLC‐DAD Determination of Furosemide in Tablets Using a Short Home‐Made Column

Abstract

Furosemide is a loop diuretic widely used as an antihypertensive. Its analysis, in pharmaceutical formulations, is often required for quality control and to develop new formulations. The aim of this work is to describe the development of a fast chromatographic procedure to determine furosemide in tablets. Adequate sample masses were prepared by dissolution of furosemide in ethanol with the aid of an ultrasonic bath, followed by filtration. After dilution, an aliquot was injected into the chromatographic system. The separations were obtained in a C18 home‐made column (50×4.6 mm, 3 µm) with methanol:phosphate buffer (10 mmol L⁻¹, pH 5.5) (30∶70) as the mobile phase, at a flow rate of 1.0 mL min⁻¹. A photodiode array detector (DAD) monitored signals between 190 and 380 nm, with special attention to 237 nm. The findings were 1.4%–6.2% intra‐assay precision; 1.6%–6.1% interassay precision (day and operator); recoveries of 90.2%, 97.5%, and 109.2% at 90%, 100%, and 110% concentration levels, respectively. The total chromatographic run lasted 3 minutes. By means of peak purity, obtained using the DAD, no interference of concomitants was observed. The residual graphic demonstrates the adequate linearity of the studied concentration interval. The proposed method was applied to commercial samples and shown to be less time and solvent consuming than the procedures previously reported in the literature.

Keywords:

• Antihypertensive drug analysis
• furosemide determination
• home‐made column

The authors are gratefull to CNPq, CAPES, and FAPESP (proc n° 04/08550‐0, n° 03/02630‐0, and n° 04/00407‐4) for financial support.