Simultaneous quantification of oxybutynin and its active metabolite N‐desethyl oxybutynin in rat plasma by ultra‐high‐performance liquid chromatography–tandem mass spectrometry and its application in a pharmacokinetic study of oxybutynin transdermal patch

Abstract

A rapid, selective and sensitive ultra‐high‐performance liquid chromatography–tandem mass spectrometry method was developed to simultaneously determine oxybutynin and its active metabolite N‐desethyl oxybutynin in rat plasma. A 0.1 mL sample of plasma was extracted with n‐hexane. Chromatographic separation was performed on a UPLC BEH C18 column (2.1 × 100 mm i.d.,1.7 μm) with mobile phase of methanol–water (containing 2 mmol/L ammonium acetate and 0.1% formic acid; 90:10, v/v). The detection was performed in positive selected reaction monitoring mode. Each plasma sample was chromatographed within 3 min. The linear calibration curves were obtained in the concentration range of 0.0944–189 ng/mL (r ≥ 0.99) for oxybutynin and 0.226–18.0 ng/mL (r ≥ 0.99) for N‐desethyl oxybutynin. The intra‐ and inter‐day precision (relative standard deviation) values were not more than 14% and the accuracy (relative error) was within ±7.6%. The method described was superior to previous methods for the quantitation of oxybutynin with three product ions and was successfully applied to a pharmacokinetic study of oxybutynin and its active metabolite N‐desethyl oxybutynin in rat plasma after transdermal administration.

Common Cholinergic, Noradrenergic, and Serotonergic Drugs Do Not Block VNS-Mediated Plasticity

“…Doses were selected based on reported ranges that produced intended pharmacological effects but were below levels found to cause analogous unwanted effects observed in clinical use. All drugs have plasma half-lives that fall within the timing of behavioral training ( Jaillon, 1980 ; Chae et al, 2013 ; Tian et al, 2019 ). Groups received motor training paired with VNS and daily injections of oxybutynin chloride (10 mg/kg, s.c., Fisher Scientific, Hampton, NH, United States – 18604931), prazosin hydrochloride (5 mg/kg, s.c., Fisher Scientific, Hampton, NH, United States – AAJ61712MD), duloxetine (20 mg/kg, s.c., Fisher Scientific, Hampton, NH, United States – D42231G), or saline (s.c.).…”

Voltammetric Determination of Oxybutynin Hydrochloride Utilizing Pencil Graphite Electrode Decorated with Gold Nanoparticles

“…The literature comprises different methods for the determination of OXB either alone, in combination with other drugs or in presence of its degradation product. Some of these methods include: spectrophotometric methods [3][4][5], HPLC [6][7][8], gas chromatography [9,10], thin layer chromatography [5], capillary electrophoresis [11] and potentiometric methods [12][13][14][15]. To the best of our knowledge, only one voltammetric method has been applied for the analysis of OXB using differential pulse and square wave cathodic adsorptive stripping voltammetry on mercury electrode surface [16].…”