U.S. PHARMACOPEIA

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Soluble Bacitracin Methylene Disalicylate
» Soluble Bacitracin Methylene Disalicylate is a mixture of bacitracin methylene disalicylate and Sodium Bicarbonate. It has a potency of not less than 8 Bacitracin Units per mg, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
Labeling— Label it to indicate that it is for veterinary use only.
pH 791: between 8.0 and 9.5, in a solution containing 25 mg of specimen per mL.
Loss on drying 731 Dry about 100 mg, accurately weighed, in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours: it loses not more than 8.5% of its weight.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay— Transfer an accurately weighed quantity of Soluble Bacitracin Methylene Disalicylate to a high-speed glass blender jar. Add 99.0 mL of sodium bicarbonate solution (1 in 50) and 1.0 mL of polysorbate 80, and blend for about 3 minutes. Proceed as directed for bacitracin under Antibiotics—Microbial Assays 81, adding a sufficient volume of 0.01 N hydrochloric acid to an accurately measured volume of this solution so that the amount of hydrochloric acid in the Test Dilution will be the same as in the median dose level of the Standard, and quantitatively diluting with Buffer No. 1 to obtain a Test Dilution having a concentration of bacitracin assumed to be equal to the median dose level of the Standard.
Auxiliary Information— Staff Liaison : Ian DeVeau, Ph.D., Associate Director
Expert Committee : (VET05) Veterinary Drugs 05
USP29–NF24 Page 235
Phone Number : 1-301-816-8178