High-performance liquid chromatographic method for the determination of esmolol hydrochloride

A rapid high-performance liquid chromatographic method for the determination of esmolol hydrochloride, a new ultra-short-acting beta blocker, is described. The stability-indicating nature of the method was demonstrated by resolving esmolol from synthetic intermediates, potential impurities, and the product of decomposition. Reverse-phase liquid chromatography was performed with a microparticulate (10-micron) cyano-bonded silica-packed column, a fixed-wavelength UV absorbance detector (lambda = 280 nm), and a mobile phase of acetonitrile-0.005 M sodium acetate-acetic acid (15:84:1) pumped at 2 mL/min. The internal standard was 2-p-chlorophenyl-2-methylpropanol. A percent RSD of less than 1.7% and an accuracy (100% - mean error) of greater than 98.6% were achieved over the concentration range studied (100-500 micrograms/mL), with correlation coefficients greater than 0.9996.