Medium: 0.1Nhydrochloric acid;900mL.

Apparatus 1: 100rpm.

Time: 45minutes.

Procedure— Determine the amount of C22H24N2O9dissolved from UVabsorbances at the wavelength of maximum absorbance at about 353nm of filtered portions of the solution under test,suitably diluted with Dissolution Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Oxytetracycline RSin the same medium.

Tolerances— Not less than 75%(Q)of the labeled amount of C22H24N2O9is dissolved in 45minutes.

Tetrabutylammonium hydrogen sulfate solution,Edetate disodium solution,pH7.5Phosphate buffer,Mobile phase,Standard preparation,Resolution solution,andChromatographic system— Proceed as directed in the Assayunder Oxytetracycline.

Assay preparation— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 100mg of oxytetracycline,to a 500-mLvolumetric flask,add about 25mLof 0.01Nhydrochloric acid,and mix.Dilute with 0.01Nhydrochloric acid to volume,and mix.Filter a portion of this solution through a 0.5-µm or finer porosity filter,and use the filtrate as the Assay preparation.

Procedure— Proceed as directed for Procedurein the Assayunder Oxytetracycline.Calculate the quantity,in mg,of C22H24N2O9in the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Oxytetracycline RSin the Standard preparation,and the other terms are as defined therein.