Tetracycline Boluses »Tetracycline Boluses contain the equivalent of not less than 90.0percent and not more than 120.0percent of the labeled amount of tetracycline hydrochloride (C22H24N2O8·HCl). Packaging and storage— Preserve in tight containers. Labeling— Label Boluses to indicate that they are intended for veterinary use only. USP Reference standards á11ñ USP Tetracycline Hydrochloride RS. Identification— Shake a suitable quantity of finely powdered Boluses with methanol to obtain a solution containing the equivalent of 1mg of tetracycline hydrochloride per mL,and filter.Using the filtrate as the Test Solution,proceed as directed under Identification—Tetracyclines á193ñ. Uniformity of dosage units á905ñ: meet the requirements for Weight Variation. Loss on drying á731ñ Dry about 100mg of finely powdered Boluses,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 3.0%of its weight,or where the Boluses have a diameter of greater than 15mm,it loses not more than 6.0%of its weight. Assay— Transfer not less than 2Boluses to a high-speed blender jar containing an accurately measured volume of 0.1Nhydrochloric acid,so that the solution so obtained contains not less than 150µg of tetracycline hydrochloride per mL,and blend for about 3to 5minutes.Proceed as directed for tetracycline under Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of this solution diluted quantitatively and stepwise with water to obtain a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard. Auxiliary Information— Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist Expert Committee:(VET)Veterinary Drugs USP28–NF23Page 1885 Phone Number:1-301-816-8178