Validated HPLC‐UV method for determination of naproxen in human plasma with proven selectivity against ibuprofen and paracetamol

Abstract

Estimating the influence of interfering compounds present in the biological matrix on the determination of an analyte is one of the most important tasks during bioanalytical method development and validation. Interferences from endogenous components and, if necessary, from major metabolites as well as possible co-administered medications should be evaluated during a selectivity test. This paper describes a simple, rapid and cost-effective HPLC-UV method for the determination of naproxen in human plasma in the presence of two other analgesics, ibuprofen and paracetamol. Sample preparation is based on a simple liquid-liquid extraction procedure with a short, 5 s mixing time. Fenoprofen, which is characterized by a similar structure and properties to naproxen, was first used as the internal standard. The calibration curve is linear in the concentration range of 0.5-80.0 µg/mL, which is suitable for pharmacokinetic studies following a single 220 mg oral dose of naproxen sodium. The method was fully validated according to international guidelines and was successfully applied in a bioequivalence study in humans. Copyright © 2015 John Wiley & Sons, Ltd.

Replicates Number for Drug Stability Testing during Bioanalytical Method Validation—An Experimental and Retrospective Approach

“…Stability results for nine drugs were recorded during method validations conducted under Good Laboratory Practice conditions at the former Pharmaceutical Research Institute in Warsaw, Poland ( [11][12][13][14][15], and unpublished data). The following types of stability were studied: short-term stability, freeze and thaw stability, long-term stability at temperatures of −14 • C and −65 • C. Nine drugs with LC-MS and HPLC-UV methods of determination of varying precision were selected to create the data sets.…”

A concise review on analytical profile of naproxen

“…2 Similar to added NSAIDS naproxen is capable of creating troubles in the gastro intestinal tract naproxen is practically insoluble in water, soluble in ethanol 96 percent and pka in methanol 4.2. 3 Naproxen is generally metabolized to 6-0-desmethyl naproxen and mutually parent and metabolized do not produce metabolizing enzymes. The practically observed incurable exclusion half-life is almost 15 hours.…”