Optimization and Validation of a Sensitive HPLC–PDA Method for Simultaneous Determination of Torasemide and Spironolactone in Human Plasma using Central Composite Design

Abstract

A sensitive, accurate, precise and rapid HPLC-PDA method was developed and validated for the simultaneous determination of torasemide and spironolactone in human plasma using Design of experiments. Central composite design was used to optimize the method using content of acetonitrile, concentration of buffer and pH of mobile phase as independent variables, while the retention factor of spironolactone, resolution between torasemide and phenobarbitone; and retention time of phenobarbitone were chosen as dependent variables. The chromatographic separation was achieved on Phenomenex C 18 column and the mobile phase comprising 20 mM potassium dihydrogen ortho phosphate buffer (pH-3.2) and acetonitrile in 82.5:17.5 v/v pumped at a flow rate of 1.0 mL min-1. The method was validated according to USFDA guidelines in terms of selectivity, linearity, accuracy, precision, recovery and stability. The limit of quantitation values were 80 and 50 ng mL-1 for torasemide and spironolactone respectively. Furthermore, the sensitivity and simplicity of the method suggests the validity of method for routine clinical studies.

Determination of torasemide in human plasma and its bioequivalence study by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry

“…A detailed comparison of methods for the determination of torasemide in human biological samples is showed in Table 8 . The developed method of the study is more sensitive than all other methods developed for determination of torasemide as a single analyte in human plasma [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] . In addition, the proposed method uses less plasma (200 μL) than many other reported methods, and has better human compliance for volunteers in bioequivalence and pharmacokinetic studies.…”

“…A rapid, sensitive and reliable determination of torasemide in human plasma is essential to evaluating its pharmacokinetics in clinical trials and bioequivalence researches. Several methods have been reported including gas chromatography–tandem mass spectrography (GC–MS) [9] , capillary zone electrophoresis (CZE) [10] , high-performance liquid chromatography–tandem ultraviolet detection (HPLC–UV) [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] and high-performance liquid chromatography–tandem electrochemical detection (HPLC–ED) [20] , [21] , [22] to determine the concentration of torasemide as a single analyte [9] , [12] , [18] , [19] , [20] , [21] or in combination with its important metabolites [10] , [11] , [13] , [14] , [15] , [16] or with other diuretic drugs [23] , [24] in plasma [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] or other biological samples [9] , [13] , [20] , [21] , [22] , [23] , [24] . Barroso et al [9] applied GC–MS to determine the concentration of torasemide in human urine, which needs complicated preparation for derivatization and is not suitable for bioequivalence studies of large quantity of samples.…”

“…Barroso et al [9] applied GC–MS to determine the concentration of torasemide in human urine, which needs complicated preparation for derivatization and is not suitable for bioequivalence studies of large quantity of samples. Additionally, several studies used HPLC with low sensitivity detectors [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] . These methods cannot detect the low concentration points such as the last several points in elimination phase, which will lead to inaccurate pharmacokinetic parameters.…”

Simultaneous determination of 5 diuretic drugs using an HPLC method by quantitative analysis of multiple components by a single marker

“…Currently, several analytical methods have been reported by HPLC for the quantification of furosemide, torasemide, azosemide, bumetanide, or etacrynic acid either alone or in combination with other drugs, both in their prescribed forms and in biological fluids [9][10][11][12][13][14][15][16][17][18][19][20][21]. The abovementioned methods, however, have not been employed for the simultaneous quantification of the five LDs in any pharmaceutical formulation.…”

Development and validation of combined dosage form of Torsemide and Spironolactone in Ultra-violet spectroscopy by simultaneous equation method

“…Literature survey revealed that several analytical methods are developed for TOR and SPI individually and combined dosage forms. HPLC [7][8][9][10][11][12] ,HPTLC 13, and UV 14 method have been developed for TOR and SPI in pharmaceutical dosage form. To best of our knowledge UV simultaneous equation method have been reported for estimation of TOR and SPI in combined dosage form.…”