Simultaneous Determination of Oxycodone and Noroxycodone in Dog Plasma and Urine by HPLC, with Post‐column Chemiluminescence Detection Using Electrogenerated tris(2,2′‐Bipyridyl) Ruthenium(III)

Abstract

A sensitive and specific method was developed for the determination of oxycodone (OXC) and its metabolite, noroxycodone (NOC), in dog plasma and urine by high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection. Plasma samples were treated with a disposable C18‐bonded column to extract oxycodone and noroxycodone. Urine samples were treated by dilution with water. The analytes were separated on the reversed phase HPLC column and detected by CL with electrochemically oxidized tris(2,2′‐bipyridyl) ruthenium(III). The assay concentration ranges for OXC and NOC were 0.5–250 ng/mL and 2.5–1250 ng/mL in dog plasma, and 0.1–40 µg/mL and 0.5–200 µg/mL in dog urine, respectively. Recoveries of the compounds from plasma and urine were more than 87%. In the within‐run and between‐run assay, the precision values were not more than 13.3%, and the accuracy values were between −3.6% and +15.0%, respectively. The methods were applied to the pharmacokinetic study of oxycodone in dogs.