Imipramine Hydrochloride Injection
»Imipramine Hydrochloride Injection is a sterile solution of Imipramine Hydrochloride in Water for Injection.It contains,in each mL,not less than 11.5mg and not more than 13.5mg of C19H24N2·HCl.
Packaging and storage— Preserve in single-dose containers,preferably of Type Iglass.
Identification— Transfer 10mLof Injection to a separator,add 2mLof 2Nhydrochloric acid,extract with 10mLof chloroform,filter,and evaporate the chloroform solution to about 2mL.Carefully add ether until the liquid becomes turbid,heat on a steam bath to produce a clear solution,then cool,and allow to stand.Filter the crystalline precipitate,wash with ether,and dry in vacuum at 105for 30minutes:the precipitate so obtained responds to Identificationtest Aunder Imipramine Hydrochloride.
Bacterial endotoxins á85ñ— It contains not more than 5.0USP Endotoxin Units per mg of imipramine hydrochloride.
pHá791ñ: between 4.0and 5.0.
Other requirements— It meets the requirements under Injections á1ñ.
Assay— Transfer an accurately measured volume of Injection,equivalent to about 25mg of imipramine hydrochloride,to a 100-mLvolumetric flask,add 0.5Nhydrochloric acid to volume,and mix.Pipet 10mLof this solution into a separator,add 10mLof 1Nsodium hydroxide,and extract with four 20-mLportions of ether,shaking each portion for 2minutes and collecting the extracts in a second separator.Extract the combined ether extracts with four 20-mLportions of 0.5Nhydrochloric acid,and combine the extracts in a 250-mLbeaker.Aerate this solution with nitrogen to remove residual ether,then transfer to a 100-mLvolumetric flask,and rinse the beaker with 0.5Nhydrochloric acid,collecting the rinsings in the flask.Add the 0.5Nacid to volume,and mix.Dissolve an accurately weighed quantity of USP Imipramine Hydrochloride RSin 0.5Nhydrochloric acid,and dilute quantitatively and stepwise with the same solvent to obtain a Standard solution having a known concentration of about 25µg per mL.Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 250nm,with a suitable spectrophotometer,using 0.5Nhydrochloric acid as the blank.Calculate the quantity,in mg,of C19H24N2·HCl in each mLof the Injection taken by the formula:
(C/V)(AU/AS),
in which Cis the concentration,in µg per mL,of USP Imipramine Hydrochloride RSin the Standard solution,Vis the volume,in mL,of Injection taken,and AUand ASare the absorbances of the solution from the Injection and the Standard solution,respectively.
Auxiliary Information— Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 1003
Phone Number:1-301-816-8330