Simultaneous Determination of Losartan and Hydrochlorothiazide in Human Plasma by LC/MS/MS with Electrospray Ionization and Its Application to Pharmacokinetics

Abstract

A method based on a simple liquid-liquid extraction (LLE) followed by high-performance liquid chromatography with negative ion electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) detection was developed for the simultaneous determination of losartan (LOS) and hydrochlorothiazide (HCTZ) in human plasma, using valsartan (VAL) and chlorthalidone (CHTD) as an internal standard, respectively. The acquisition was performed in multiple reactions monitoring (MRM) and the limit of quantification was 4 ng/mL for both LOS and HCTZ. The method was linear in the studied range (4-800 ng/mL for LOS and 4-500 ng/mL for HCTZ). The intra-assay precisions ranged from 2.6-11.9% for LOS and 1.4-8.2% for HCTZ, while the inter-assay precisions ranged from 1.0-8.0% for LOS and 2.5-7.7% for HCTZ. The intra-assay accuracies ranged from 91.3 to 107.6% for LOS and 91.5 to 105.8% for HCTZ, while the inter-assay accuracies ranged from 99.9 to 106.4% for LOS and 97.4 to 101.4% for HCTZ. The analytical method was applied to a bioequivalence study, in which 28 healthy adult volunteers (14 men) received single oral doses (100 mg LOS + 25 mg HCTZ) of reference and test formulations, in an open, two-period, balanced randomized, crossover protocol. Based on the 90% confidence interval of the individual ratios for Cmax and AUC0-inf, it was concluded that the test formulation is bioequivalent to the reference Hyzaar formulation with respect to the rate and extent of absorption of both LOS and HCTZ.

Losartan

“…Plasma concentrations of losartan and losartan acid (LA) were determined by LC-MS/MS. Salvadori et al [43] developed a method based on a simple liquid-liquid extraction (LLE) followed by HPLC with negative ion ESI tandem mass spectrometry (HPLC-ESI-MS/MS) detection for the simultaneous determination of losartan (LOS) and hydrochlorothiazide (HCTZ) in human plasma, using valsartan (VAL) and chlorthalidone (CHTD) as an IS, respectively. The acquisition was performed in multiple reaction monitoring (MRM) and the limit of quantification was 4 ng/mL for both LOS and HCTZ.…”

A modified serial blood sampling technique and utility of dried-blood spot technique in estimation of blood concentration: application in mouse pharmacokinetics

“…Also, the run time of the method was only 2.4 min with the use of UPLC, which further increased the throughput. Various methods are reported in literature for the quantitation of amodiaquine (Stepniewska et al 2009), chloroquine (Hodel et al 2009;Singhal et al 2007) and chlorthalidone (Khuroo et al 2008;Salvadori et al 2009) in plasma. However, all the reported methods use time and resource-intensive extraction methods or have a long run time.…”

A New HPLC Method for Determination of Losartan in Human Plasma and its Application in Bioequivalence Studies

“…Losartan should be administered orally once or twice daily for a total daily dose of 25-100 mg. 3 Last studies showed that several HPLC ,LC/MS/MS methods were used for determination of losartan and its metabolite in human plasma. [4][5][6][7][8][9][10][11][12] The aim of this study was to develop a simple, rapid sensitive and reliable HPLC method with Ultraviolent detection for quantization of losartan in human plasma samples and to compare the bioavailability of two losartan tablets (50 mg) formulations (losartan from Iranian company, as a test formulation and COZAR, MSD ,The Netherlands as a reference formulation) . The method was validated according to procedures and acceptance criteria based on FDA guideline and recommendations of ICH, to provide enough selectivity, sensitivity and reliability in pharmacokinetic and bioequivalence studies.…”