Tetrabutylammonium hydrogen sulfate solution, Edetate disodium solution, pH 7.5 Phosphate buffer, Mobile phase, Standard preparation, System suitability solution, and Chromatographic system— Proceed as directed in the Assay under Oxytetracycline.

Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute Oxytetracycline for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and dilute quantitatively with 0.01 N hydrochloric acid to obtain a solution having a concentration of about 0.2 mg of oxytetracycline per mL.

Assay preparation 2 (where the label states the quantity of oxytetracycline in a given volume of constituted solution)—Constitute Oxytetracycline for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with 0.01 N hydrochloric acid to obtain a solution having a concentration of about 0.2 mg of oxytetracycline per mL.

Procedure— Proceed as directed for Procedure in the Assay under Oxytetracycline. Calculate the quantity, in mg, of oxytetracycline (C22H24N2O9) withdrawn from the container or in the portion of constituted solution taken by the formula: in which L is the labeled quantity, in mg, of oxytetracycline (C22H24N2O9) in the container or in the portion of constituted solution taken; D is the concentration, in mg per mL, of oxytetracycline in Assay preparation 1 or in Assay preparation 2, based on the labeled quantity in the container or in the portion of constituted solution taken, respectively, and the extent of dilution; and the other terms are as defined therein.