PHARMACOKINETIC STUDY OF LONG-ACTING OXYT ETRACYCLINE IN COWS

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 sensibilit y of 0.312 mu g/ml. The mean residence time (MRT) was 20.68+/-5.55 h a nd the half life was 9.63+/-4.04 h. The maximal OTC concentration (7.5 3+/-2.20 mu g/ml) was observed after 8.42+/-3.43 h. Serum concentratio n >1 mu g/ml was maintained for about 39.57+/-13.15 hours.