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 Dihydrostreptomycin Sulfate RS.

Loss on drying á731ñ— Dry about 100mg,accurately weighed,of finely ground Boluses in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60for 3hours:it loses not more than 10.0%of its weight.

Assay— Proceed as directed for the cylinder-plate assay of dihydrostreptomycin under Antibiotics—Microbial Assays á81ñ,using 3Boluses added to a mixture of 499.0mLof Buffer No.3and 1.0mLof polysorbate 80and blended for 5minutes in a high-speed glass blender jar.Allow to stand for not less than 1hour,and repeat the blending.While stirring this mixture,withdraw an accurately measured volume of it,and dilute quantitatively and stepwise with Buffer No.3to obtain a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.

Expert Committee:(VET)Veterinary Drugs

USP28–NF23Page 650

Phone Number:1-301-816-8178