Main content area

Regulatory control of glycopyrrolate in performance horses using validated UHPLC/MS–MS methods

Rumpler, M.J., Sams, R.A., Colahan, P.
Journal of chromatography 2012 v.889-890 pp. 130-137
Thoroughbred, accuracy, chromatography, detection limit, horses, intravenous injection, linear models, oral administration, regression analysis, urine
We describe a validated, rapid, sensitive, and specific UHPLC–MS/MS method to detect and quantify glycopyrrolate in 0.5mL of horse urine. Further, we investigated the elimination of glycopyrrolate in urine after both intravenous and oral administration of clinically relevant doses to Thoroughbred horses. Quantification was performed by weighted, linear regression analysis using a deuterated analogue of glycopyrrolate as internal standard (IS). The method was characterized by a linear range of 5–2500pg/mL, a lower limit of quantification of 5pg/mL and a limit of detection of 1pg/mL. The intra and inter-batch imprecisions were <10% RSD and accuracy of the method ranged between 94 and 104%. Glycopyrrolate remained detectable in urine samples collected through 168h after intravenous administration and through 24h after oral administration. Analytical method validation requirements for linearity, specificity, precision, accuracy, stability, dilution integrity, matrix effect, and ruggedness have been fulfilled. The urine method described in this report is simple and efficient and is the first reported method with sufficient sensitivity, accuracy, and precision to regulate the use of glycopyrrolate in urine samples collected more than one day after dosing of horses. Urine to plasma glycopyrrolate concentration ratios were calculated and were approximately 100:1 in samples collected from 24h through the end of sample collection.