Estimation of ramipril and telmisartan in human plasma by LC–MS/MS: Application in pharmacokinetic study

Abstract

AbstractA highly sensitive and specific liquid chromatography–tandem mass spectrometry method has been developed for simultaneous estimation of Ramipril and Telmisartan in human plasma using Ramipril d5 and telmisartan d3 as internal standards. Liquid chromatography–tandem mass spectrometry was operated under the multiple reaction monitoring mode using the electrospray ionization technique. Simple liquid–liquid extraction process was used to extract Ramipril, Telmisartan, and internal standard from human plasma. The total run time was 2.5 min and the elution of ramipril and telmisartan were 0.97 and 1.17 min, respectively. This was achieved with a mobile phase consisting of 2 mM ammonium acetate in 0.1% formic acid as mobile phase A and 100% acetonitrile as mobile phase B in the ratio 20:80 with a flow rate of 0.7 mL/min on a betasil C18 column. The developed method was validated in human plasma with a lower limit of quantitation of 0.5 and 0.98 ng/mL for ramipril and telmisartan, respectively. A linear response function was established for the range of concentrations 0.5–50.0 ng/mL (r > 0.998) and 0.98–800.0 ng/mL (r > 0.998) for ramipril and telmisartan, respectively. The intra‐ and interday precision values for ramipril and telmisartan met the acceptance as per United States Food and Drug Administration guidelines. Ramipril and telmisartan were stable in a battery of stability studies viz., bench‐top, auto‐sampler, and freeze–thaw cycles, long‐term matrix stability. The developed method was applied to a pharmacokinetic study in humans.