Simultaneous determination of althiazide and spironolactone in tablets by high-performance liquid chromatography

Successive ratio subtraction as a novel manipulation of ratio spectra for quantitative determination of a mixture of furosemide, spironolactone and canrenone

Furosemide and spironolactone are commonly prescribed antihypertensive drugs. Canrenone is the main degradation product and main metabolite of spironolactone. Ratio subtraction and extended ratio subtraction spectrophotometric methods were previously applied for quantitation of only binary mixtures. An extension of the above mentioned methods; successive ratio subtraction, is introduced in the presented work for quantitative determination of ternary mixtures exemplified by furosemide, spironolactone and canrenone. Manipulating the ratio spectra of the ternary mixture allowed their determination at 273.6nm, 285nm and 240nm and in the concentration ranges of (2-16μgmL^-1), (4-32μgmL^-1) and (1-18μgmL^-1) for furosemide, spironolactone and canrenone, respectively. Method specificity was ensured by the application to laboratory prepared mixtures. The introduced method was ensured to be accurate and precise. Validation of the developed method was done with respect to ICH guidelines and its validity was further ensured by the application to the pharmaceutical formulation. Statistical comparison between the obtained results and those obtained from the reported HPLC method was achieved concerning student's t-test and F ratio test where no significant difference was observed.

Spironolactone voltammetric determination on renewable amalgam film electrode

In this study a new high sensitive method of spironolactone (SP) determination is proposed using voltammetric technique. As the working electrode amalgam film silver based electrode (Hg(Ag)FE) was applied, that resulted in obtaining low limit of spironolactone detection, ex. for the preconcentration time 45 s obtained detection limit was 4.7·10^-9 mol L^-1 (1.96·10^-6 g L^-1). The linear response of spironolactone signal on mercury film electrode was obtained in the range of concentration from 15·10^-9 to 3.0·10^-6 mol L^-1 and the obtained repeatability measured as RSD was very good, with the value of 2.0% (n = 5; concentration 0.5·10^-6 mol L^-1). The proposed method was successfully applied and validated by studying the recovery in commercially available pharmaceutical formulations containing known amount of spironolactone.

An Improved High-Performance Liquid Chromatography Assay for Spironolactone Analysis

This study prepared an extemporaneously formulated liquid suspension dosage form (5 mg/ml) from commercially available 25 mg tablets. Stability-indicating HPLC assay procedures were established and utilized to analyze the concentration of the drug. The method proved to be a simple model since it does not contain a buffer system. The mobile phase used was the same as that suggested by the manufacturer for the storage of the column. Therefore, the solvent system saves analytical processing time, since it does not require a change in the mobile phase before or after the analysis. The analytical method has been shown to be stability-indicating. The results have shown that there is no interference from any of the degradation products obtained from stressing spironolactone by heat and extremes in pH or with the internal standard, hydrocortisone 21-acetate.

High-performance liquid chromatography methods for the separation and quantitation of spironolactone and its degradation products in aqueous formulations and of its metabolites in rat serum

HPLC assays have been developed for the determination of spironolactone and its degradation products 7 alpha-thiospirolactone and canrenone in aqueous solutions of beta-cyclodextrins and for the determination of spironolactone and its metabolites 7 alpha-thiospirolactone, 7 alpha-thiomethylspirolactone, 6 beta-hydroxy-7 alpha-thiomethylspirolactone and canrenone in rat serum samples. Both methods were well suited for their respective applications, i.e., studying the stability of spironolactone in liquid formulations of beta-cyclodextrins and the oral absorption of spironolactone in rats. The HPLC method developed for spironolactone and its metabolites in rat serum requires very small volumes of serum making it possible to take several blood samples over a period of time.

Analysis of diuretic doping agents by HPLC screening and GC-MSD confirmation

The simultaneous analysis of 14 diuretics in human urine (belonging to five different pharmacological groups) by reversed-phase high-performance liquid chromatography (HPLC) with a diode-array detector was developed by using a gradient elution with acetonitrile and phosphate buffer containing propylamine hydrochloride on a Bondclone-ODS (10 microns) column. The method was applied to the screening test of several diuretics abused by athletes. The confirmation analysis was performed by gas chromatography-mass spectrometry with ion-selective detection (GC-MSD). The characteristic mass fragment ions obtained by electron-impact (EI) ionization (70 eV) provided sufficient identification of these diuretic agents. During the 1990 weight-lifting contest of Asia in Kao-Hsiung, Republic of China, one urine sample was found positive for the diuretic hydrochlorothiazide.