Imipramine Hydrochloride Tablets
»Imipramine Hydrochloride Tablets contain not less than 93.0percent and not more than 107.0percent of the labeled amount of imipramine hydrochloride (C19H24N2·HCl).
Packaging and storage— Preserve in tight containers.
Identification— Powder a suitable number of Tablets,equivalent to about 100mg of imipramine hydrochloride,and macerate the powder with 10mLof chloroform.Filter the chloroform extract through paper into a wide-mouth test tube,and evaporate the filtrate to about 3mL.Carefully add ether until the liquid becomes turbid,heat on a steam bath to produce a clear solution,then cool,and allow to stand.The precipitate that is formed may be recrystallized from acetone.Filter the crystalline precipitate,wash with ether,and dry in vacuum at 105for 30minutes:the precipitate so obtained meets the requirements for Identificationtest Aunder Imipramine Hydrochloride.
Dissolution á711ñ—
Medium: 0.01Nhydrochloric acid;900mL.
Apparatus 1: 100rpm.
Time: 45minutes.
Procedure— Determine the amount of C19H24N2.HCl dissolved by employing UVabsorption at the wavelength of maximum absorbance at about 250nm on filtered portions of the solution under test,suitably diluted with Medium,in comparison with a Standard solution having a known concentration of USP Imipramine Hydrochloride RSin the same Medium.
Tolerances— Not less than 75%(Q)of the labeled amount of C19H24N2·HCl is dissolved in 45minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Procedure for content uniformity— Transfer 1finely powdered Tablet to a 100-mLvolumetric flask with the aid of 70mLof dilute hydrochloric acid (1in 100),and shake by mechanical means for 30minutes.Add dilute hydrochloric acid (1in 100)to volume,mix,and filter,if necessary,discarding the first 20mLof the filtrate.Transfer an aliquot of the filtrate,equivalent to about 2.5mg of imipramine hydrochloride,to a 100-mLvolumetric flask,add dilute hydrochloric acid (1in 100)to volume,and mix.Dissolve an accurately weighed quantity of USP Imipramine Hydrochloride RSin dilute hydrochloric acid (1in 100),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 dilute hydrochloric acid (1in 100)as the blank.Calculate the quantity,in mg,of C19H24N2·HCl in the Tablet by the formula:
10(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 the aliquot taken of the solution from the Tablet;and AUand ASare the absorbances of the solution from the Tablet and the Standard solution,respectively.
Assay— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 100mg of imipramine hydrochloride,to a 200-mLvolumetric flask,add about 100mLof dilute hydrochloric acid (1in 25),and shake vigorously by mechanical means for 1hour.Add the dilute acid to volume,mix,and filter,discarding the first 20mLof the filtrate.Pipet 5mLof the filtrate into a separator,and proceed as directed in the Assayunder Imipramine Hydrochloride Injection,beginning with “add 10mLof 1Nsodium hydroxide.”Calculate the quantity,in mg,of imipramine hydrochloride (C19H24N2·HCl)in the portion of Tablets taken by the formula:
4C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Imipramine Hydrochloride RSin the Standard solution;and AUand ASare the absorbances of the solution from the Tablets 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