title: Simultaneous determination of amiloride and hydrochlorothiazide in human plasma by liquid chromatography/tandem mass spectrometry with positive/negative ion-switching electrospray ionisation.
abstract: A new method for simultaneous determination of amiloride and hydrochlorothiazide by liquid chromatography/electrospray tandem mass spectrometry (LC/MS/MS) operated in positive and negative ionization switching mode was developed and validated. Protein precipitation with acetonitrile was selected for sample preparation. The analytes were separated on a Phenomenex Curosil-PFP (250x4.6 mm, 5 microm) column by a gradient elution with a mobile phase consisting of 0.15% formic acid solution containing 0.23% ammonium acetate and methanol pumped at a flow rate of 1.0 mL.min(-1). Rizatriptan was used as the internal standard (IS) for quantification. The determination was carried out on a Waters Quattro-micro triple-quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) mode using the following transitions monitored simultaneously: positive m/z 230-->171 for amiloride, m/z 270-->158 for rizatriptan, and negative m/z 296-->205 for hydrochlorothiazide. The lower limits of quantification (LLOQs) were 0.1 and 1.0 ng.mL(-1) for amiloride and hydrochlorothiazide, respectively, which were lower than other published methods by using ultraviolet (UV), fluorimetric or mass spectrometric detection. The intra- and inter-day precision and accuracy were studied at three different concentration levels and were always better than 15% (n=5). This simple and robust LC/MS/MS method was successfully applied to the pharmacokinetic study of compound amiloride and hydrochlorothiazide tablets in healthy male Chinese volunteers.
authors: Department of Pharmaceutical Analysis, China Pharmaceutical University, 24 Tongjia Lane, Nanjing 210009, China.
authors: Min
authors: M
authors: Song
authors: Taijun
authors: T
authors: Hang
authors: Hua
authors: H
authors: Zhao
authors: Li
authors: L
authors: Wang
authors: Ping
authors: P
authors: Ge
authors: Pengcheng
authors: P
authors: Ma
mesh_terms: D000284:Administration, Oral; D000584:Amiloride / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D004232:Diuretics / Q000097:blood* / Q000493:pharmacokinetics; D004359:Drug Therapy, Combination; D006801:Humans; D006852:Hydrochlorothiazide / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D015203:Reproducibility of Results; D017366:Serotonin Receptor Agonists / Q000097:blood; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014230:Triazoles / Q000097:blood; D014363:Tryptamines / Q000097:blood
chemical_list: D004232:Diuretics; D017366:Serotonin Receptor Agonists; D014230:Triazoles; D014363:Tryptamines; D006852:Hydrochlorothiazide; C093622:rizatriptan; D000584:Amiloride