Internal standard solution ,Standard preparation,and Chromatographic system—Prepare as directed in the Assayunder Spectinomycin Hydrochloride.

Assay preparation 1— Suspend the contents of 1container of Spectinomycin for Injectable Suspension in water,and dilute quantitatively with water to obtain a stock solution containing about 20mg of spectinomycin per mL.Transfer 1.0mLof this solution to a glass-stoppered,25-mLconical flask,and freeze-dry.Add 10.0mLof Internal standard solutionand 1.0mLof hexamethyldisilazane,and shake intermittently for 1hour.

Assay preparation 2 (where the label states the quantity of spectinomycin in a given volume of constituted suspension)—Constitute 1container of Spectinomycin for Injectable Suspension in a volume of water,accurately measured,corresponding to the volume of diluent specified in the labeling.Dilute an accurately measured portion of the constituted suspension quantitatively with water to obtain a stock solution containing about 20mg of spectinomycin per mL.Transfer 1.0mLof this solution to a glass-stoppered,25-mLconical flask,and freeze-dry.Add 10.0mLof Internal standard solutionand 1.0mLof hexamethyldisilazane,and shake intermittently for 1hour.

Procedure— Proceed as directed in the Assayunder Spectinomycin Hydrochloride.Calculate the quantity,in g,of C14H24N2O7in the container of Spectinomycin for Injectable Suspension taken to prepare Assay preparation 1taken by the formula: in which L1is the labeled quantity,in g,of C14H24N2O7in the container,and D1is the concentration,in mg per mL,of spectinomycin in the stock solution used to prepare Assay preparation 1,on the basis of the labeled quantity in the container and the extent of dilution,and the other terms are as defined therein.Calculate the quantity,in mg,of C14H24N2O7in each mLof constituted Injectable Suspension taken to prepare Assay preparation 2taken by the formula: in which L2is the labeled quantity,in mg,of C14H24N2O7in each mLof constituted suspension of Spectinomycin for Injectable Suspension,and D2is the concentration,in mg per mL,of spectinomycin in the stock solution used to prepare Assay preparation 2,on the basis of the labeled quantity in each mLof constituted suspension and the extent of dilution.