High‐throughput LC‐MS/MS assay for 6‐methoxy‐2‐naphthylacetic acid, an active metabolite of nabumetone in human plasma and its application to bioequivalence study

Abstract

A simple, precise and accurate assay for the determination of 6-methoxy-2-naphthylacetic acid (6-MNA), an active metabolite of nabumetone in human plasma, was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The analyte (6-MNA) and propranolol (internal standard, IS) were extracted from 200 microL aliquot of human plasma via solid-phase extraction employing HLB Oasis cartridges and separated on a Discovery HS C18 (50 x 4.6 mm, 5 microm) column. Detection of analyte and IS was done by tandem mass spectrometry with a turbo ion spray interface operating in positive ion and multiple reaction monitoring acquisition mode. The total chromatographic runtime was 3.0 min with retention time for 6-MNA and IS at 1.97 and 1.26 min, respectively. The method was validated over a dynamic linear range of 0.20-60.00 microg/mL for 6-MNA with mean correlation coefficient r > or = 0.9986. The intra-batch and inter-batch precision (%CV) across five validation runs (lower limit of quantiation, low-, medium- and high-quality controls and upper limit of quantitation) was less than 7.5%. The accuracy determined at these levels was within -5.8 to +0.2% in terms of percentage bias. The method was successfully applied for a bioequivalence study of 750 mg nabumetone tablet formulation in 12 healthy Indian male subjects under fasted condition.

Carbon-Carbon Bond Cleavage in Activation of the Prodrug Nabumetone

“…The mass spectrometer was operated in the positive ion mode using electrospray (ES) to monitor the precursor to product ion transition of m/z 229.3 → 171.1 for nabumetone and 217.3 → 171.1 for 6-MNA, as previously published (Patel et al, 2008). Nabumetone and its derivatives were analyzed using the total ion current signal and the extracted ion for the specific mass.…”

Applicability of LC/MS/MS assay for 6‐methoxy‐2‐napthylacetic acid to support the bioequivalence study of nabumetone—comments on the research work of Patel et al. (2008)

“…Interestingly, Patel et al (2008) have developed an excellent assay to enable the determination of the active metabolite, 6-methoxy-2-napthylacetic acid (6-MNA), following oral dosing with nabumetone. The development and validation of the assay has been painstakingly performed to ensure that all required elements are addressed and/or well justified as per the present day needs (Patel et al, 2008).…”

“…Applicability of LC/MS/MS assay for 6-methoxy-2-napthylacetic acid to support the bioequivalence study of nabumetonecomments on the research work of Patel et al (2008) To the EditorIn recent years, many publications have appeared in BMC that utilize state of the art laboratory tools for development and validation of assays for the applicability to bioequivalence studies in human volunteers (Georgita et al, 2008;Patel et al, 2008;Medvedovici et al, 2008;Sora et al, 2007;Nirogi et al, 2006). Interestingly, all of these published assays support both parent and/or active metabolite(s) exposure measurements to facilitate pharmacokinetic characterization and/or bioequivalence assessment of the derived parameters between test and reference products.…”

“…In the application of this newly developed assay for 6-MNA, Patel et al (2008) have performed a bioequivalence study in 12 healthy subjects using a two-treatment, two-period, two-sequence, randomized crossover design. The pharmacokinetic parameters derived for 6-MNA from the two products (test vs the reference) is also reported in a tabular format in the published work (Patel et al, 2008).…”

“…The development and validation of the assay has been painstakingly performed to ensure that all required elements are addressed and/or well justified as per the present day needs (Patel et al, 2008).…”