Dissolution á711ñ
Medium:
water;900mL.
Apparatus 2:
75rpm.
Time:
60minutes.
Procedure
Determine the amount of C
22H
24N
2O
9dissolved from UVabsorbances at the wavelength of maximum absorbance at about 273nm of filtered portions of the solution under test,suitably diluted with water,in comparison with a Standard solution having a known concentration of
USP Oxytetracycline RSin the same medium,using 5mLof 0.1Nhydrochloric acid to dissolve the Standard.
Tolerances
Not less than 80%(Q)of the labeled amount of C22H24N2O9is dissolved in 60minutes.
Loss on drying á731ñ
Dry about 100mg of Capsule contents,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60

for 3hours:it loses not more than 5.0%of its weight.
Assay
Tetrabutylammonium hydrogen sulfate solution
,
Edetate disodium solution,
pH7.5Phosphate buffer,
Mobile phase,
Standard preparation,Resolution solution,and
Chromatographic systemProceed as directed in the
Assayunder
Oxytetracycline.
Assay preparation
Remove,as completely as possible,the contents of not less than 20Capsules,and mix.Transfer an accurately weighed portion of the powder,equivalent to about 100mg of oxytetracycline,to a 500-mLvolumetric flask,add about 50mLof 0.01Nhydrochloric acid,and swirl to dissolve.Dilute with 0.01Nhydrochloric acid to volume,mix,and filter a portion of the solution through a 0.5-µm or finer porosity filter.Use the filtrate as the Assay preparation.
Procedure
Proceed as directed for
Procedurein the
Assayunder
Oxytetracycline.Calculate the quantity,in mg,of oxytetracycline (C
22H
24N
2O
9)in the portion of Capsules taken by the formula:
0.5(CP)(rU/rS),
in which the terms are as defined therein.