Bio-equivalence study of two tilmicosin phosphate formulations (Micotil 300® and Cozina 300®) in broiler chickens

Background: The present study was designed to assess the comparative bio-equivalence of Micotil 300® and Cozina 300® in healthy broiler chickens after oral administration of both products in a dose of 15 mg tilmicosin base/kg body wt.Methods: 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 Micotil 300®, while the 2nd group was designed to study the pharmacokinetics of Cozina 300®. Each broiler chicken in both groups was orally administered with 15 mg tilmicosin/kg body 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.Results: The disposition kinetics of Micotil 300® and Cozina 300® following oral administration of 15 mg tilmicosin/kg body wt revealed that the maximum blood concentration [Cmax] were 1.73 and 1.67 μg/ml and attained at [tmax] of 2.01 and 2.04 hours, respectively.Conclusions: Cozina 300® is bioequivalent to Micotil 300® since the ratios of Cmax, AUC0-24 andAUC0-∞ (T/R) were 0.96, 0.93 and 0.91 respectively. These are within the bio-equivalence acceptance range. Micotil 300® and Cozina 300® are therefore bioequivalent and interchangeable