Determination of clavulanic acid in calf plasma by liquid chromatography tandem mass spectrometry

Abstract

A method for the quantification of clavulanic acid in calf plasma using high-performance liquid chromatography combined with electrospray ionization (ESI) mass spectrometry, operating in the negative ionization mode (LC-MS/MS), is presented. Sample preparation includes a simple and fast deproteinization with acetonitrile and a back-extraction of the acetonitrile with dichloromethane. Chromatography is performed on a reversed-phase PLRP-S polymeric column using 0.05% formic acid in water and acetonitrile. The limit of quantification is 25 ng/ml, which is lower than other published methods using ultraviolet (UV), fluorimetric or mass spectrometric detection. The limit of detection is calculated to be 3.5 ng/ml. The stability of clavulanic acid was demonstrated according to The Guidelines of Bioanalytical Method Validation of The Food and Drug Administration (FDA): freeze and thaw stability, short-term stability, long-term stability, stock solution stability and postpreparative stability. The method is used in a pharmacokinetic and bioequivalence study of amoxycillin/clavulanic acid formulations in calves.

Rapid and Simultaneous Quantitation of Amoxicillin and Clavulanic Acid in Human Plasma and Urine by Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry and Its Application to a Pharmacokinetic Study

“…Both amoxicillin and clavulanic acid show high polarity. 25,26 The solid phases of Acquity BEH C18, Phonomenex Kinetex XB-C18 and Acquity HSS T3 were tested for separation. Also, the HSS T3 column was finally selected because of its 100% compatibility with the aqueous phase, nice peak shape and low baseline noise signal.…”

Quantification of seven β-lactam antibiotics and two β-lactamase inhibitors in human plasma using a validated UPLC-MS/MS method

“…Calibrators were prepared in 0.066 M aqueous phosphate buffer (pH 6) as described by Reyns et al [9]. Briefly, a stock solution was prepared by weighing 10 mg of each compound and dissolving these compounds altogether in 100.0 mL of phosphate buffer.…”

Validated LC-MS/MS Method for the Concomitant Determination of Amoxicillin and Clavulanic Acid from Human Plasma

“…There are several methods known in the literature for the individual and/or simultaneous determination of amoxicillin and clavulanic acid in human plasma and other biological matrix using UV [2,6,11,13] and MS/MS methods [3][4][5][7][8][9]12]. All MS/MS methods involve polarity switching, for monitoring the clavulanic acid in negative electrospray ionization mode.…”