Concentrations of tylvalosin and 3‐O‐acetyltylosin attained in the synovial fluid of swine after administration by oral gavage at 50 and 5 mg/kg

Abstract

The objectives of this study were to determine the concentration of tylvalosin (TVN) and its metabolite, 3-O-acetyltylosin (3AT) in the synovial fluid of growing pigs when administered as a single bolus by oral gavage at target doses of 50 mg/kg (Trial 1) and 5 mg/kg (Trial 2). TVN is a water soluble macrolide antimicrobial used in swine production. The stability of the drug in synovial fluid samples stored at -70 °C up to 28 days was also evaluated in Trial 2. In Trial 1, eight pigs were randomly assigned to one of eight time points for euthanasia and synovial fluid collection: 0, 1, 2, 3, 4, 6, 9, 12 h postgavage. For Trial 2, 24 pigs were randomly allocated to one terminal collection time point at 0, 2, 4, 6, 8 or 10 h postgavage. Synovial fluid was analyzed to determine TVN and 3AT concentrations. TVN and 3AT were detected in Trial 1 at all time points, except 0 h. At 2 h postgavage for trial 2, the mean concentrations peaked at 31.17 ng/mL (95% CI: 18.62-52.16) for TVN and at 58.82 ng/mL (95% CI: 35.14-98.46) for 3AT. Storage duration did not impact TVN or 3AT concentrations (P-value 0.9732).

Variation in water disappearance, daily dose, and synovial fluid concentrations of tylvalosin and 3‐O‐acetyltylosin in commerical pigs during five day water medication with tylvalosin under field conditions

“…The extraction and detection methods used to quantify TVN and 3AT in the synovial samples is reported in Canning et al. (). For plasma samples, the procedures reported in Canning et al.…”

“…For plasma samples, the procedures reported in Canning et al. () were performed using blank plasma in lieu of synovial fluid for the calibration curves. The plasma samples were diluted with 400 μl of acetonitrile containing 0.1% formic acid, vortexed, and centrifuged for 20 min at 630 g .…”

“…The mobile phase began at 35% B with a linear gradient to 98% B at 6.3 min, followed by re-equilibration to 35% B.Separation was achieved using a Gemini C18 column (50 × 2.0 mm, 3 μm particles, 110 Å, Phenomenex, Torrance, CA, USA) at room temperature. The standard curve of TVN and 3AT concentration was linear from 1 to 1,000 ng/ml and was accepted when the correlation coefficient exceeded 0.95 and measured values were within 20% of the actual values.The extraction and detection methods used to quantify TVN and 3AT in the synovial samples is reported inCanning et al (2016). For plasma samples, the procedures reported inCanning et al (2016) were performed using blank plasma in lieu of synovial fluid for the calibration curves.…”

“…The standard curve of TVN and 3AT concentration was linear from 1 to 1,000 ng/ml and was accepted when the correlation coefficient exceeded 0.95 and measured values were within 20% of the actual values.The extraction and detection methods used to quantify TVN and 3AT in the synovial samples is reported inCanning et al (2016). For plasma samples, the procedures reported inCanning et al (2016) were performed using blank plasma in lieu of synovial fluid for the calibration curves. The plasma samples were diluted with 400 μl of acetonitrile containing 0.1% formic acid, vortexed, and centrifuged for 20 min at 630 g. The supernatant was poured off, dried down, and reconstituted with 200 μl of 25% (v/v) acetonitrile.…”

“…The plasma samples were diluted with 400 μl of acetonitrile containing 0.1% formic acid, vortexed, and centrifuged for 20 min at 630 g. The supernatant was poured off, dried down, and reconstituted with 200 μl of 25% (v/v) acetonitrile. The extraction, detection and standard curves were as perCanning et al (2016).…”