Development and validation of a gas chromatography‐mass spectrometry method for the determination of phenazopyridine in rat plasma: application to the pharmacokinetic study

Abstract

Phenazopyridine hydrochloride is a strong analgesic used in the treatment of urinary tract infections. The aim of the present study was to develop a procedure based on gas chromatography-mass spectrometry (GC-MS) for the analysis of phenazopyridine in rat plasma. The method was set up and adapted for the analysis of small biological samples taken from rats. Biological samples were extracted by liquid-liquid extraction. The extraction agent was ethyl acetate. The samples were separated by GC on a DB-5MS analytical column and determined by a quadrupole mass spectrometer detector operated under selected ion monitoring mode. Excellent linearity was found between 0.01 and 1.00 microg/ml (r = 0.9991, n = 9) for plasma samples. The limit of detection (LOD) was 0.3 ng/ml. Within-day and between-day precisions expressed as the relative standard deviation (RSD) for the method were 1.83-4.91% and 2.12-4.76%, respectively. The recoveries for all samples were >90%. The main pharmacokinetic parameters obtained were T(max) = (0.35+/-0.01) h, C(max) = (0.396+/-0.079) microg/ml, AUC = (0.373+/-0.065) h microg/ml and CL = (94.2+/-5.9) ml/g/h. The results presented here clearly indicate that this proposed method could be applicable to investigate the pharmacokinetic of phenazopyridine in rats after administration. (c)

Method development and validation: Skills and tricks

“…[22,23] Because of the ongoing advances in analytical chemistry technologies, analytical methods are updated over time; thus, validation and cross validation of methods become important for accurate interpretation of data collected over years. [24][25][26][27][28][29] Validation is performed with a formal, approved, and signed methods validation protocol in quality assurance (QA) unit. …”

PEEK tube‐based online solid‐phase microextraction–high‐performance liquid chromatography for the determination of yohimbine in rat plasma and its application in pharmacokinetics study

“…The detailed plasma collecting method was shown in our previous work (Chen et al, 2007;Chen et al, 2011).…”

A novel GC–MS method for determination of chrysophanol in rat plasma and tissues: Application to the pharmacokinetics, tissue distribution and plasma protein binding studies

“…In addition, GC-MS is an important analytical tool for MS detection performed in selected ion monitoring (SIM) mode by which the sensitivity can be increased. The applications of GC-MS in the study the pharmacokinetics and tissue distribution of active compounds in herbs have been well investigated by our groups [13][14][15]. However, there are still no reports for the determination of chrysophanol by GC-MS.…”