title: Determination of methocarbamol in equine serum and urine by high-performance liquid chromatography with ultraviolet detection and atmospheric pressure ionization-mass spectrometric confirmation.
abstract: Urine and serum samples collected from four standard-bred mares after and oral regimen administration of methocarbamol were extracted and analyzed. The method consisted of enzyme hydrolysis followed by a one-step liquid-liquid extraction, separation on a reversed-phase (RP-18) column, and detection using an ultraviolet (UV) detector. The confirmation was carried out using a liquid chromatography-atmospheric pressure ionization-mass spectrometry (LC-API-MS) system. Maximum methocarbamol concentrations of 1498, 1734, 1547, 2322 micrograms/mL in urine and 4.9, 1.7, and 3.6 micrograms/mL in serum were observed. The peak concentrations of the drug were detected 1-4 h (urine) and 10-60 min (serum) after administration to four horses. The method validation results and drug elimination profiles for both urine and serum are presented and discussed.
authors.affiliation: Can Test Laboratories Ltd., Vancouver, British Columbia, Canada.
authors.forename: M R
authors.initials: MR
authors.lastname: Koupai-Abyazani
authors.forename: B
authors.initials: B
authors.lastname: Esaw
authors.forename: B
authors.initials: B
authors.lastname: Laviolette
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006736:Horses / Q000097:blood* / Q000652:urine; D013058:Mass Spectrometry / Q000379:methods*; D008721:Methocarbamol / Q000097:blood* / Q000652:urine; D009125:Muscle Relaxants, Central / Q000097:blood* / Q000652:urine; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009125:Muscle Relaxants, Central; D008721:Methocarbamol