Tetracycline Hydrochloride Capsules »Tetracycline Hydrochloride Capsules contain not less than 90.0percent and not more than 125.0percent of the labeled amount of C22H24N2O8·HCl. Packaging and storage— Preserve in tight,light-resistant containers. USP Reference standards á11ñ USP Tetracycline Hydrochloride RS.USP4-Epianhydrotetracycline Hydrochloride RS. Identification— The chromatogram of the Assay preparationobtained as directed in the Assayexhibits a major peak for tetracycline,the retention time of which corresponds to that exhibited in the chromatogram of the Standard preparationobtained as directed in the Assay. Dissolution á711ñ Medium: water;900mL. Apparatus 2: 75rpm.Maintain a distance of 45±5mm between the blade and the inside bottom of the vessel. Time: 60minutes;90minutes for 500-mg capsules. Procedure— Determine the amount of C22H24N2O8·HCl dissolved from UVabsorbances at the wavelength of maximum absorbance at about 276nm 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 Tetracycline Hydrochloride RSin the sameMedium. Tolerances— Not less than 80%(Q)of the labeled amount of C22H24N2O8·HCl is dissolved in 60minutes;90minutes for 500-mg capsules. Uniformity of dosage units á905ñ: meet the requirements. 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 60for 3hours:it loses not more than 4.0%of its weight. Limit of 4-epianhydrotetracycline— Using the Diluting solvent,Chromatographic system,and Procedureset forth in the Assay,chromatograph a Standard solution prepared by dissolving an accurately weighed quantity of USP4-Epianhydrotetracycline Hydrochloride RSin Diluting solventto obtain a solution having a known concentration of about 10µg per mL.Using the chromatogram so obtained and the chromatogram of the Assay preparationobtained as directed in the Assay,calculate the percentage of 4-epianhydrotetracycline hydrochloride in the Capsules taken by the formula: (10CE/T)(rU/rS), in which CEis the concentration,in µg per mL,of USP4-Epianhydrotetracycline Hydrochloride RSin the Standard solution;Tis the quantity,in mg,of tetracycline hydrochloride in the portion of Capsules taken to prepare the Assay preparation,based on the labeled quantity;and rUand rSare the 4-epianhydrotetracycline peak responses obtained from the Assay preparationand the Standard solution,respectively:not more than 3.0%is found. Assay— Diluting solvent,Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Prepare as directed in the Assayunder Tetracycline Hydrochloride. Assay preparation— Weigh accurately not fewer than 20Capsules.Empty the Capsule contents into a mortar.Clean and accurately weigh the Capsule shells,and calculate the net weight of the Capsule contents.Mix the powder in the mortar,using a pestle,and transfer an accurately weighed quantity of the freshly mixed powder,equivalent to about 50mg of tetracycline hydrochloride,to a 100-mLvolumetric flask.Add about 50mLof Diluting solvent,mix,and sonicate for about 5minutes.Allow to cool,dilute with Diluting solventto volume,mix,and filter. Procedure— Proceed as directed in the Assayunder Tetracycline Hydrochloride.Calculate the quantity,in mg,of C22H24N2O8·HCl in the portion of Capsules taken by the formula: (CP/10)(rU/rS), in which the terms are as defined therein. Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow Expert Committee:(PA7)Pharmaceutical Analysis 7 USP28–NF23Page 1886 Phone Number:1-301-816-8335