Tetracycline Oral Suspension »Tetracycline Oral Suspension is Tetracycline with or without one or more suitable buffers,preservatives,stabilizers,and suspending agents.It contains the equivalent of not less than 90.0percent and not more than 125.0percent of the labeled amount of tetracycline hydrochloride (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. Uniformity of dosage units á905ñ FORSUSPENSION PACKAGED IN SINGLE-UNIT CONTAINERS :meets the requirements. Deliverable volume á698ñ: meets the requirements. pHá791ñ: between 3.5and 6.0. 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 in the Oral Suspension taken by the formula: (25CE/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 equivalent in the portion of Oral Suspension taken,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 5.0%is found. Assay— Diluting solvent,Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Prepare as directed in the Assayunder Tetracycline Hydrochloride. Assay preparation— Transfer an accurately measured volume of Oral Suspension,equivalent to about 125mg of tetracycline hydrochloride,to a 250-mLvolumetric flask,add 200mLof Diluting solvent,and shake.Add Diluting solventto volume,mix,and filter. Procedure— Proceed as directed in the Assayunder Tetracycline Hydrochloride.Calculate the quantity,in mg per mL,of C22H24N2O8·HCl equivalent in the Oral Suspension taken by the formula: (CP/4V)(rU/rS), in which Vis the volume,in mL,of Oral Suspension taken,and the other terms are as defined therein. Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow Expert Committee:(PA7)Pharmaceutical Analysis 7 USP28–NF23Page 1885 Phone Number:1-301-816-8335