Determination of Valsartan, Candesartan, and Carvedilol in Pure and Pharmaceutical Forms Using RP-HPLC with Wavelength Programming

Abstract

A straightforward, quick, and reliable reverse-phase high-performance liquid chromatographic method for the simultaneous determination of three antihypertensive drugs (Valsartan, Candesartan, and Carvedilol) was established and validated. The drugs were separated using a C18 column with an isocratic mobile phase of methanol and water (84:16, v/v) at a temperature of 40 °C with a flow rate of 1.2 mL/min. The three drugs were detected under optimum conditions with two wavelengths; Valsartan and Candesartan were detected at 250 nm (0 to 3.0 minutes), while Carvedilol was detected at 240 nm (3.1 to 10.0 minutes). The total run time was less than 9.5 minutes, and the three drugs were well separated.

The method had a wide linear response range for each drug (1 to 25 µg/mL) with a correlation coefficient of 0.9983. The method limits of detection showed Valsartan 0.5539, Candesartan 0.2228, and Carvedilol 0.1716 µg/mL, respectively. The limits of quantitation were Valsartan 1.6785, Candesartan 0.6751, and Carvedilol 0.5201 µg/mL, respectively. The method had good accuracy (Recovery 101.32-104.25%) and precision (Relative standard deviation ≤ 3.87%).

The method was successfully used on six different commercial preparations and showed no interference from the excipients in these commercial products; the recoveries of the three drugs were between 90.22% and 99.78%. This method is a highly reliable, cost-effective, environmentally friendly alternative to common approaches for the routine quality control testing of these antihypertensive medications and improves analyte separation by using isocratic elution and wavelength programming without using a gradient.