Packaging and storage— Preserve in tight containers.

Labeling— Label Boluses to indicate that they are for veterinary use only.

USP Reference standards 11— USP Neomycin Sulfate RS.

Identification— Blend a Bolus with 250 mL of water. Filter a portion of the suspension obtained. If necessary, dilute a portion of the filtrate with water to obtain a test solution containing about 2 mg of neomycin per mL. Dissolve a quantity of USP Neomycin Sulfate RS in water to obtain a Standard solution containing about 2 mg of neomycin per mL. Separately apply 1 µL of each solution to a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture. Develop the chromatogram in a solvent system consisting of a mixture of water, butyl alcohol, glacial acetic acid, and pyridine (35:30:22:6) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, and dry at about 110 for about 5 minutes. Spray the plate evenly with a solution of ninhydrin (2 mg per mL), and dry the plate at about 100 for about 5 minutes. Locate the spots on the plate: the RF value of the principal spot in the chromatogram obtained from the test solution corresponds to that of the principal spot in the chromatogram obtained from the Standard solution.

Uniformity of dosage units 905: meet the requirements for Weight Variation.

Disintegration 701: 60 minutes.

Residual solvents 467: meet the requirements.

Assay— Proceed as directed for the assay of neomycin under Antibiotics—Microbial Assays 81, the Test Dilution being prepared as follows. Blend an accurately counted number of Boluses (not less than 2) at high speed in a blender jar with a sufficient accurately measured volume of Buffer No. 3 to obtain a stock solution having a convenient concentration. Dilute this stock solution quantitatively and stepwise with Buffer No. 3 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.

Expert Committee : (VET05) Veterinary Drugs 05

USP29–NF24 Page 1491

Phone Number : 1-301-816-8178