Pharmacokinetics of oxytetracycline in hybrid catfish (Clarias macrocephalus x C. gariepinus) after intravascular and oral administrations.

Over the past decade, catfish farming has increased in Southeast Asia. However, there has been no existing for pharmacokinetic data in the hybrid catfish (Clarias macrocephalus x C. gariepinus). This study was designed to evaluate the pharmacokinetic characteristics of oxytetracycline (OTC) in the hybrid catfish, following single intravascular (IV) or oral (PO) administration at a single dosage of 50 mg/kg body weight (BW). In total, 140 catfish (each about 100-120 g BW) were divided into two groups (n = 70). Blood samples (0.6-0.8 mL) were collected from ventral caudal vein at pre-assigned times up to 144 h (sparse samples design). OTC plasma concentrations were analyzed using high-performance liquid chromatography-photodiode array detector. The pharmacokinetic parameter of OTC was evaluated using a non-compartment model. OTC plasma concentrations were detectable for up to 144 and 120 h after IV and PO, respectively. The elimination half-life value of OTC was long with slow clearance after IV administration in hybrid catfish. The average maximum concentration value of OTC was 2.72 µg/mL with a time at the maximum concentration of 8 h. The absolute PO bioavailability was low (2.47%). These results showed that PO administration of OTC at a dosage of 50 mg/kg BW was unlikely to be effective for clinical use in catfish. The pharmacodynamic properties and clinical efficacy of OTC after multiple medicated feed are warranted.

Poapolathep A ，Sriphairoj K ，Hatachote S ，Wongpanit K ，Saensawath D ，Klangkaew N ，Phaochoosak N ，Giorgi M ，Poapolathep S ... -  《-》

Comparative pharmacokinetics of oxytetracycline in rainbow trout (Salmo gairdneri) and African catfish (Clarias gariepinus).

Grondel JL ，Nouws JF ，Schutte AR ，Driessens F ... -  《JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS》

Penetration of oxytetracycline into the nasal secretions and relationship between nasal secretions and plasma oxytetracycline concentrations after oral and intramuscular administration in healthy pigs.

The penetration of oxytetracycline (OTC) in plasma and nasal secretions of healthy pigs was evaluated during the first study, in response to oral dose of 20 mg of OTC per kg of body weight (bwt) per day as a 400 mg/kg feed medication (n = 5) and to intramuscular (i.m.)-administered formulations at 10 mg/kg bwt (n = 5), 20 mg/kg bwt (n = 5), 40 mg/kg bwt (n = 5). Concentrations of OTC in plasma and nasal secretions were determined by a validated ultra-high performance liquid chromatography associated to tandem mass spectrometry method (UPLC/MS/MS). The objectives were to select the efficacy treatment and to evaluate the possibility to predict nasal secretions concentrations from those determined in plasma. The animals were housed together in each experiment. In each group, the treatment was administered once daily during 6 consecutive days, and nasal secretions and plasma were collected after 4 and 24 h at day 2 and day 6. For oral administration, only one medicated feed was prepared and distributed to all the animals together and was consumed in approximately 1 h. To meet recommendations of efficacy for OTC in nasal secretions, only the i.m. of 40 mg/kg bwt associated to an inter-dosing interval of 24 h provides and maintains concentrations in nasal secretions ≥1 μg/mL, appropriate to the MIC 50 and 90 of Pasteurella multocida and Bordetella bronchiseptica, respectively, the main pathological strains in nasal secretions. It has been demonstrated that, using a generalized linear mixed model (GLMM), OTC in the nasal secretions (μg/mL) can be predicted taking into account the OTC concentrations in plasma (μg/mL), according to the following equation: OTC(nasal secretions)  = 0.28 OTC(plasma) -1.49. In a second study, the pharmacokinetic behaviour of OTC in plasma and nasal secretions of healthy pigs was investigated, after single-dose i.m. of 40 mg/kg bwt of the drug. Blood samples and nasal secretions were collected at predetermined times after drug administration. The data collected in 10 pigs for OTC were subjected to non-compartmental analysis. In plasma, the maximum concentration of drug (C(max) ), the time at which this maximum concentration of drug (T(max) ) was reached, the elimination half-life (t½) and the area under the concentration vs. time curve (AUC) were, respectively, 19.4 μg/mL, 4.0, 5.1 h and 150 μg·h/mL. In nasal secretions, C(max) , T(max) , t½ and AUC were, respectively, 6.29 μg/mL, 4.0, 6.6 h and 51.1 μg·h/mL.

Bimazubute M ，Cambier C ，Baert K ，Vanbelle S ，Chiap P ，Gustin P ... -  《-》

Pharmacokinetics of danofloxacin in African catfish (Clarias gariepinus) after intravenous and intramuscular administrations.

Aboubakr M ，Soliman A 《ACTA VETERINARIA HUNGARICA》

Pharmacokinetics of oxytetracycline in broiler chickens following different routes of administration.

The aim of this study was to determine the pharmacokinetics of oxytetracycline (OTC) in broiler chickens following intravenous (IV), intramuscular (IM), subcutaneous (SC) and oral (PO) administrations at a dose of 15 mg/kg bodyweight. Plasma concentrations of OTC were determined using liquid chromatography-tandem mass spectrometry and non-compartmental pharmacokinetic analysis was then conducted. The absorption half-life time was 1.23 ± 0.36 h, 1.19 ± 0.52 h, and 0.49 ± 0.38 h after IM, SC and PO administration, respectively. The elimination half-life time was 27.41 ± 6.06 h, 10.23 ± 4.20 h, 7.83 ± 0.56 h, and 14.86 ± 9.23 h, and the mean residence time was 9.67 ± 1.7 h, 11.45 ± 1.76 h, 11.38 ± 0.59 h, and 10.37 ± 3.91 h after IV, IM, SC and PO administration, respectively. Bioavailability was 76.88 ± 12.90%, 92.20 ± 10.53% and 12.13 ± 4.56% after IM, SC and PO administration, respectively, which indicated that OTC is poorly absorbed from the gastrointestinal tract in broiler chickens.

Ziółkowski H ，Grabowski T ，Jasiecka A ，Zuśka-Prot M ，Barski D ，Jaroszewski JJ ... -  《-》