Oxytetracycline (calcium)

Oxytetracycline calcium is an antibiotic belonging to the tetracycline class. Oxytetracycline calcium potently inhibits Gram-negative and Gram-positive bacteria. Oxytetracycline calcium is a protein synthesis inhibitor and prevents the binding from aminoacil-tRNA to the complex m-ribosomal RNA. Oxytetracycline calcium also possesses anti-HSV-1 activity^[1][2][3]. In Vitro: Oxytetracycline calcium is an important member of the bacterial aromatic polyketide family, which is a structurally diverse class of natural products. Oxytetracycline calcium is synthesized by a type II polyketide synthase that generates the poly-beta-ketone backbone through successive decarboxylative condensation of malonyl-CoA extender units, followed by modifications by cyclases, oxygenases, transferases, and additional tailoring enzymes^[2]. In Vivo: The effects of administration a therapeutic dose of Oxytetracycline (82.8 mg/kg of bw to 1 % bw/day) calcium for 10 days are species specific. Oxytetracycline calcium increases the relative liver weight in Morone chrysops x M. saxatilis, the enzymatic activity of CYP3A4 in Ictalurus punctatus, protein expression of CYP3A4 in Oreochromis niloticus and depleted the hepatic CYP3A4 in the latter^[1].
For Oxytetracycline calcium, the limits are 100 μg/kg in muscle and milk, 200 μg/kg in egg, 300 μg/kg in liver and 600 μg/kg in kidney. Oxytetracycline calcium is administered to fish as medicated feed at concentrations ranging from 35 to 75 mg a.i kg-1 biomass day-1 for 7-14 days^[1].