Abstract

BIOEQUIVALENCE STUDY OF TWO ORAL OXYTETRACYCLINE FORMULATIONS (OXYTETRACYCLINE 50%® AND TETRAMED®) IN BROILER CHICKENS

Ashraf Elkomy*

ABSTRACT

The present study was designed to assess the comparative bio-equivalence of Oxytetracycline 50%® and Tetramed® in healthy broiler chickens after oral administration of both products in a dose of 20 mg oxytetracycline/kg.b.wt. Twenty four broiler chickens were divided into two groups. The first group was designed to study the pharmacokinetics of Oxytetracycline 50%®, while the 2nd group was designed to study the pharmacokinetics of Tetramed®. Each broiler chicken in both groups were injected intravenously with 20 mg oxytetracycline standard/kg.b.wt. Blood samples were obtained from the wing vein and collected immediately before and at 0.08, 0.16, 0.25, 0.5, 1, 2, 4, 8, 12 and 24 hours after a single intravenous or oral administration. Oxytetracycline in both products obeyed a two compartments open model following I.V. injection in a dose of 20 mg/kg.b.wt. The disposition kinetics of Oxytetracycline 50%® and Tetramed® following oral administration of 20 mg oxytetracycline base/kg.b.wt. revealed that the maximum blood concentration [Cmax] were 3.60 and 3.14 μg/ml and attained at [tmax] of 0.97 and 1.01 hours, respectively. The mean systemic bioavailability of oxytetracycline in Oxytetracycline 50%® and Tetramed® after oral administration in healthy chickens was 91.17 and 89.57%, respectively. In conclusion: Tetramed® is bioequivalent to Oxytetracycline 50%® since the ratios of Cmax, AUC0-24 and AUC0-∞ (T/R) were 0.87, 0.88 and 0.87 respectively. These are within the bioequivalence acceptance range. Tetramed® and Oxytetracycline 50%® are therefore bioequivalent and interchangeable.

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