Simultaneous analysis of allopurinol and oxypurinol using a validated liquid chromatography–tandem mass spectrometry method in human plasma

Abstract

The present study describes a simple, reliable and reproducible liquid chromatography–tandem mass spectrometry method (LC–MS/MS) for the simultaneous determination of allopurinol and its active metabolite, oxypurinol in human plasma for a pharmacokinetic/bioequivalence study. After protein precipitation (PPT) of 100 µL plasma sample with 1.0% formic acid in acetonitrile, the recovery of the analytes and allopurinol-d2 as an internal standard ranged from 85.36% to 91.20%. The analytes were separated on Hypersil Gold (150 mm×4.6 mm, 5 µm) column using 0.1% formic acid-acetonitrile (98:2, v/v) as the mobile phase. Quantification was done using electrospray ionization in the positive mode. The calibration concentration range was established from 60.0 to 6000 ng/mL for allopurinol and 80.0–8000 ng/mL for oxypurinol. Matrix effect in human plasma, expressed as IS-normalized matrix factors ranged from 1.003 to 1.030 for both the analytes. The developed method was found suitable for a clinical study with 300 mg allopurinol tablet formulation in healthy subjects.

Ultra-performance hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry for simultaneous determination of allopurinol, oxypurinol and lesinurad in rat plasma: Application to pharmacokinetic study in rats

“…[ 18 , 19 ]. Several methods have been reported in literature for simultaneous determination of ALP and OXP in human plasma [ 20 – 24 ]. Recently, Zhou XY et al, described the assay for the determination of LES in rat plasma by UPLCMS/MS method [ 25 ].…”

Technologies to improve the sensitivity of existing chromatographic methods used for bioanalytical studies

“…Protein precipitation (PPT) is widely used in biological analysis, especially for high‐throughput screening, due to its fast, simple, and cost‐efficient characteristics (Feng, Liu, Wang, & Di, ; Zhao et al, ). Moreover, PPT often provides higher recovery of analytes when compared with solid‐phase extraction (SPE) and liquid–liquid extraction (LLE) after optimizing the most appropriate precipitation reagent (Rathod et al, ; Wang et al, ). For example, Zhu et al () compared the ratios of methanol to acetonitrile from 1:1 to 5:1 (v/v), and ultimately chose 4:1 (v/v) as the optimal ratio for plasma sample extraction to achieve maximal recovery and minimal matrix effects.…”

Developing, optimizing, and assessing a green electrophoretic method for determination of benzbromarone and allopurinol with its active metabolite in biological and pharmaceutical matrices

“…This is to ensure the reduction or elimination of the perilous substances utilized in the method or produced as waste [15, 16]. From the analytical point of view, some chromatographic methods were described to determine both AL and its active metabolite [17–21], or in combination with BZ [21–26], or in other combination [27]. The suggested method is the first CZE method that is used to determine the combined drugs with the active metabolite using a green analytical workflow.…”

“…Bearing in mind, that none of the reported methods that determined the three analytes had considered the environmental impact of the analysis. Harmful solvents and reagents, such as methanol, formic acid, acetonitrile, and sodium hydroxide, were highly used [20–28]. In view of these facts, the aims of the study are to develop, optimize, and validate a novel, green, and economic CZE method to separate and simultaneously determine BZ and AL in pharmaceutical or biological matrices in the presence of OX, the active metabolite and the oxidative degradation product of AL.…”