Cimetidine in Sodium Chloride Injection
»Cimetidine in Sodium Chloride Injection is a sterile solution of Cimetidine Hydrochloride and Sodium Chloride in Water for Injection.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of cimetidine (C10H16N6S)and not less than 95.0percent and not more than 110.0percent of the labeled amount of sodium chloride (NaCl).
Packaging and storage— Preserve in single-dose glass or plastic containers.Glass containers are preferably of Type Ior Type IIglass.
Identification—
A: The chromatogram obtained from the Assay preparationexhibits a major peak for cimetidine,the retention time of which corresponds to that of the cimetidine peak in the chromatogram of the Standard preparation,as obtained in the Assay.
B: It responds to the tests for Sodium á191ñand for Chloride á191ñ.
Bacterial endotoxins á85ñ— It contains not more than 0.5USP Endotoxin Unit per mg of cimetidine hydrochloride.
pHá791ñ: between 5.0and 7.0.
Other requirements— It meets the requirements under Injections á1ñ.
Assay for cimetidine—
Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Cimetidine Hydrochloride.
Assay preparation— Transfer an accurately measured volume of Injection,equivalent to 2mg of cimetidine,to a 200-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Procedure— Separately inject equal volumes (about 50µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the peak responses.Calculate the quantity,in mg,of cimetidine (C10H16N6S)in each mLof the Injection taken by the formula:
200(252.34/288.81)(C/V)(rU/rS),
in which 252.34and 288.81are the molecular weights of cimetidine and cimetidine hydrochloride,respectively;Cis the concentration,in mg per mL,of USP Cimetidine Hydrochloride RSin the Standard preparation;Vis the volume of Injection taken;and rUand rSare the cimetidine peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Assay for sodium chloride— Dilute an accurately measured volume of Injection quantitatively,and stepwise if necessary,with water to obtain a solution having a concentration of about 0.5mg of sodium chloride per mL.Titrate with 0.1Nsilver nitrate VS,using a silver–silver chloride electrode.Each mLof 0.1Nsilver nitrate is equivalent to 3.545mg of chloride.From the determined chloride concentration per mL,subtract the quantity,(35.453/252.35)W,to correct for the chloride present as cimetidine hydrochloride,where Wis the quantity,in mg per mL,of cimetidine in the Injection,as determined in the Assay for cimetidine.Multiply the corrected value by 1.648to obtain the quantity,in mg per mL,of sodium chloride in the volume of Injection taken.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 474
Phone Number:1-301-816-8251