Plasma bioavailability of 2 long-acting oxytetracycline formulations in the pig
Archimbault, P.; Navetat, H.; Vidal, R.; Douin, M.J.; Mignot, A.
Veterinary Research 25(4): 399-404
Two commercially available long-acting oxytetracycline (OTC-LA) formulations were administered by intramuscular injection in 2 groups of 10 clinically healthy pigs at the recommended dose level of 20 mg/kg. Plasma concentrations were analysed by high-performance liquid chromatography (HPLC) of a period of 0 to 84 h. The limit of quantification of the assay was 0.125 mu-g/ml. The comparison of the C-MAX did not reveal any significant differences (4.45 +- 1.30 and 4.40 +- 0.9 mu-g/ml). The results were similar for the T-MAX (3.60 +- 1.58 and 4.00 +- 2.67 h). The areas under the curve were also similar. The AUC-0-84 h results were respectively 92.8 +- 14.1 and 96.3 +- 11.3 mg cntdot h/l and the AUC-0- infin results were 99.5 +- 14.7 and 106.7 +- 15.4 mg cntdot h/l. No significant difference was found. This may be considered as a preliminary study to demonstrate the bioequivalence of the 2 preparations. On the basis of the statistical analysis of the results obtained, a cross-over study using 2 groups of 20 animals is theoretically necessary for such a demonstration.