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Abstract

Stereoselective metabolism of OXY was evident following both transdermal and oral administration of OXY. The reduced pre-systemic metabolism of transdermally administered OXY compared to oral administration resulted in not only significantly lower DEO plasma concentrations, but also a different metabolite pattern. The differences between R-OXY and R-DEO following the two routes of administration support the potential for comparable clinical efficacy and reduced anticholinergic side-effects with transdermal treatment.

Simultaneous quantification of the enantiomers of verapamil and its N-demethylated metabolite in human plasma using liquid chromatography–tandem mass spectrometry

“…One further advantage would be the possibility of using an isotopically labelled internal standard in order to improve the performance of the analytical method. There are a few examples in the literature of the coupling of protein-based CSPs to mass spectrometric detection using electrospray [19][20][21][22][23], thermospray [24] or atmospheric pressure chemical ionisation interfaces [25]. One major concern when developing these systems has been how the sensitivity of the ion source is affected by the high water content in the mobile phases necessary for obtaining the chiral resolution.…”

The Effects of External Heating on the Permeation of Oxybutynin through Human Epidermal Membrane

“…15,16) Because external heating is thought to be one of the possible factors changing the pharmacokinetics of OXY, we examined the permeated amounts and fluxes of OXY from the TDS of OXY through human epidermal membrane with or without heating using Franz-type diffusion cells, compared with the TDS of ISDN.…”

Enantioselective analysis of oxybutynin and N-desethyloxybutynin with application to an in vitro biotransformation study☆

“…DEO is present in the plasma at concentrations approximately 4-10 times higher than those of the parent compound and it has similar anticholinergic effects of OXY. In therapeutic use, DEO seems to contribute greatly to the anticholinergic side effects, in particular dry mouth [5,6]. The possibility of OXY delivering via non-oral route may be a more effective method of reducing the drug adverse reactions.…”

“…The possibility of OXY delivering via non-oral route may be a more effective method of reducing the drug adverse reactions. Some studies demonstrated that its intravaginal [7] and transdermal [5,6] administration avoid the pre-systemic biotransformation of OXY, minimizing the side effects.…”

“…All the authors used chiral columns based on amylose derivates [12] and acid ␣ 1 -glycoprotein [5,9]. Most of the methods for the analysis of OXY and DEO enantiomers in biological fluids are based on liquid-liquid extraction (LLE) for sample preparation.…”