Pharmacokinetic study of long-acting oxytetracycline in cows. Estudio cinético de oxitetraciclina de larga acción en bovinos de Iechería

Abstract

Pharmacokinetics of a long-acting formula of oxytetracycline (OTC) in one formulation of dymetylacetomide, was studied in seven-cows after i.m. administration (20 mg/kg of body weight). Serum OTC concentration was measured using a microbiological assay procedure with a sensibility of 0.312 μg/ml. The mean residence time (MRT) was 20.68 ± 5.55 h and the half life was 9.63 ± 4.04 h. The maximal OTC concentration (7.53 ± 2.20 μg/ml) was observed after 8.42 ± 2.43 h. Serum concentration > 1 μg/ml was maintained for about 39.57 ± 13.15 hours.