Packaging and storage
Preserve in tight containers.
Thin-layer chromatographic identification test á201BNPñ
Test solution
Shake a portion of ground Tablet powder,equivalent to about 70mg of neomycin (base),with 5mLof water,and filter.Dilute a portion of this solution with 0.1Nhydrochloric acid to obtain a solution containing the equivalent of 3.5mg of neomycin (base)per mL.It meets the requirements.
Loss on drying á731ñ
Dry about 100mg of powdered Tablets,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60

for 3hours:it loses not more than 10.0%of its weight.
Assay
Proceed as directed under
AntibioticsMicrobial Assays á81ñ,using not less than 5Tablets blended at high-speed in a blender jar for 3to 5minutes with a sufficient accurately measured volume of
Buffer No.3to obtain a stock solution having a convenient concentration.Dilute this stock solution 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.