Abstract

BIO-EQUIVALENCE STUDY OF TWO ORAL TYLOSIN-DOXYCYCLINE FORMULATIONS (STANDARD TYLOSIN-DOXYCYCLINE AND DOUBACTIN®) IN BROILER CHICKENS

Ashraf Elkomy and Mohamed Aboubakr*

ABSTRACT

The present study was designed to assess the comparative bio-equivalence of Standard tylosin-doxycycline combination and Doubactin® in healthy broiler chickens after oral administration of both products in a dose of 50 mg tylosin base and 25 mg of doxycycline base/kg.b.wt. Twenty four broiler chickens were divided equally into two groups (12 chickens for each group). The first group was designed to study the pharmacokinetics of Standard tylosin-doxycycline combination, while the 2nd group was designed to study the pharmacokinetics of Doubactin®. Each broiler chicken in both groups was orally administered with 50 mg tylosin base and 25 mg of doxycycline base/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, 6, 8, 12 and 24 hours after a single oral administration. The disposition kinetics of tylosin in Standard tylosin-doxycycline combination and Doubactin® following oral administration of 50 mg tylosin base and 25 mg of doxycycline base/kg.b.wt, revealed that the maximum blood concentration [Cmax] were 2.94 and 2.85 μg/ml and attained at [tmax] of 1.01 and 1.02 hours for both products, respectively. The disposition kinetics of doxycycline in Standard tylosin-doxycycline combination and Doubactin® following oral administration of 50 mg tylosin base and 25 mg of doxycycline base/kg.b.wt, revealed that the maximum blood concentration [Cmax] were 4.02 and 3.86 μg/ml and attained at [tmax] of 1.03 and 1.04 hours for both products, respectively.

Keywords: .