Novobiocin,monosodium salt [1476-53-5].
»Novobiocin Sodium has a potency equivalent to not less than 850µg of novobiocin (C31H36N2O11)per mg,calculated on the dried basis.
Packaging and storage Preserve in tight containers.
A: Prepare a test solution by dissolving a quantity of it in methanol to obtain a concentration of about 1mg of novobiocin per mL.Similarly prepare a Standard solution,using USP Novobiocin RS.Separately apply 1-µLportions of the test solution and the Standard solution to a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture,and allow the spots to dry.Place the plate in a chromatographic chamber equilibrated with a solvent system consisting of a mixture of chloroform,methanol,and ammonium hydroxide (75:25:1),and develop the chromatogram.When the solvent front has moved about three-fourths of the length of the plate,remove the plate from the chamber,and allow to dry.Locate the spots on the plate by examination under short-wavelength UVlight:the RFvalue of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
B: The residue obtained by igniting it responds to the tests for Sodium á191ñ.
Specific rotation á781Sñ: between -50and -58.
Test solution: 50mg per mL,in a mixture of methanol and hydrochloric acid (100:1).
Crystallinity á695ñ: meets the requirements.
pHá791ñ: between 6.5and 8.5,in a solution containing 25mg per mL.
Loss on drying á731ñ Dry about 100mg,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 6.0%of its weight.
Residue on ignition á281ñ: between 10.5%and 12.0%,the charred residue being moistened with 2mLof sulfuric acid and an ignition temperature of 550±50being used.
Assay Dissolve a suitable quantity of Novobiocin Sodium,accurately weighed,in an accurately measured volume of Buffer No.3sufficient to obtain a stock solution of convenient concentration.Proceed as directed under AntibioticsMicrobial Assays á81ñ,using an accurately measured volume of this stock solution diluted quantitatively and stepwise with Buffer No.6to yield 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