Pharmacokinetic model of florfenicol in turbot ( Scophthalmus maximus ): establishment of optimal dosage and administration in medicated feed

• Published in: Journal of Fish Diseases
• Main Authors: de Ocenda, V‐R, Almeida‐Prieto, S, Luzardo‐Álvarez, A, Barja, J L, Otero‐Espinar, F J, Blanco‐Méndez, J
• Other Authors: Junta Nacional Asesora de Cultivos Marinos (JACUMAR), Secretaría de Estado de Universidades e Investigación
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Veterinary (miscellaneous); Aquatic Science; Scophthalmus maximus; Turbot
• Online Access: http://dx.doi.org/10.1111/jfd.12525; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjfd.12525; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfd.12525

Abstract The pharmacokinetics of florfenicol ( FF ) in turbot ( Scophthalmus maximus ) was studied after single intravenous (10 mg kg −1 ) and oral (100 mg kg −1 ) administration. The plasma concentration–time data of florfenicol were described by an open one‐compartment model. The elimination half‐life ( t 1/2 ) was estimated to be 21.0 h, and the total body clearance, Cl, was determined as 0.028 L kg h −1 . The apparent volume distribution ( V d ) was calculated to be 0.86 L kg −1 and the mean residence time ( MRT iv ) was 30.2 h. Following oral administration, the maximum plasma concentration ( C max ) of 55.4 μg mL −1 was reached at 12 h ( T max ). The absorption constant ( k a ) was 0.158 h −1 . The bioavailability was estimated to be 57.1%. The low bioavailability observed at higher doses was explained by the saturation of the mechanisms of absorption. The drug absorption process was limited by its inherent low solubility, which limited the amount of available FF absorbed in the gastrointestinal tract. Based on the pharmacokinetic data, an optimal dosing schedule for FF administration is hereby provided. Based on the minimum inhibitory concentration found for susceptible strains of Aeromonas salmonicida , oral FF administration of first, an initial dose of 30 mg FF kg −1 , followed by 6 maintenance doses at 18 mg kg −1 /daily could be effective against furunculosis in turbot.