Neostigmine Methylsulfate Injection
»Neostigmine Methylsulfate Injection is a sterile solution of Neostigmine Methylsulfate in Water for Injection.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of C13H22N2O6S.
Packaging and storage— Preserve in single-dose or in multiple-dose containers,protected from light.
Identification— Transfer a volume of Injection,containing the equivalent of 1mg of neostigmine methylsulfate,to a small porcelain dish.Evaporate,if necessary,to 2mL,add 0.5mLof sodium hydroxide solution (2in 5),and proceed as directed in Identificationtest Bunder Neostigmine Methylsulfate,beginning with “evaporate on a steam bath.”
pHá791ñ: between 5.0and 6.5.
Other requirements— It meets the requirements under Injections á1ñ.
Assay—
Standard preparation— Dissolve a suitable quantity of USP Neostigmine Methylsulfate RS,accurately weighed,in water,and dilute quantitatively and stepwise with water to obtain a solution having a known concentration of about 40µg per mL.
Assay preparation— Pipet an accurately measured volume of Injection,equivalent to about 2mg of neostigmine methylsulfate,into a 50-mLvolumetric flask,add water to volume,and mix.
Procedure— Proceed as directed for Procedurein the Assayunder Neostigmine Bromide Tablets.Calculate the quantity,in mg,of C13H22N2O6Sin each mLof the Injection taken by the formula:
0.05(C/V)(AU/AS),
in which Cis the concentration,in µg per mL,of USP Neostigmine Methylsulfate RSin the Standard preparation,Vis the volume,in mL,of Injection taken,and AUand ASare the absorbances of the solutions from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 1366
Phone Number:1-301-816-8330