BIO-EQUIVALENCE STUDY OF TWO INJECTABLE TILMICOSIN FORMULATIONS (MICOTIL 300 AND COZINA 300) IN CALVES

The present study was designed to assess the comparative bio-equivalence of Micotil 300? and Cozina 300? in healthy Calves after SC injection of both products in a dose of 10 mg tilmicosin base/kg.b.wt. Ten calves were divided equally into two groups (5 calves for each group). The first group was designed to study the pharmacokinetics of Micotil 300?, while the 2nd group was designed to study the pharmacokinetics of Cozina 300?. Each calf in both groups was SC injected with 10 mg tilmicosin/kg.b.wt. Blood samples were obtained from the jugular 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 SC injection. The disposition kinetics of Micotil 300? and Cozina 300? following SC injection of 10 mg tilmicosin/kg.b.wt. revealed that the maximum blood concentration [Cmax] were 4.01 and 3.53 μg/ml and attained at [tmax] of 1.82 and 1.83 hours, respectively. In conclusion: Cozina 300? is bioequivalent to Micotil 300?since the ratios of Cmax, AUC0-24 andAUC0-∞ (T/R) were 0.88, 0.87 and 0.89 respectively. These are within the Bio-equivalence acceptance range. Micotil 300? and Cozina 300?are therefore bioequivalent and interchangeable.