Imipramine Hydrochloride Tablets
» Imipramine Hydrochloride Tablets contain not less than 93.0 percent and not more than 107.0 percent 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 100 mg of imipramine hydrochloride, and macerate the powder with 10 mL of chloroform. Filter the chloroform extract through paper into a wide-mouth test tube, and evaporate the filtrate to about 3 mL. 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 105 for 30 minutes: the precipitate so obtained meets the requirements for Identification test A under Imipramine Hydrochloride.
Dissolution 711
Medium: 0.01 N hydrochloric acid; 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Procedure— Determine the amount of C19H24N2.HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 250 nm 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 RS in the same Medium.
Tolerances— Not less than 75% (Q) of the labeled amount of C19H24N2·HCl is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Procedure for content uniformity— Transfer 1 finely powdered Tablet to a 100-mL volumetric flask with the aid of 70 mL of dilute hydrochloric acid (1 in 100), and shake by mechanical means for 30 minutes. Add dilute hydrochloric acid (1 in 100) to volume, mix, and filter, if necessary, discarding the first 20 mL of the filtrate. Transfer an aliquot of the filtrate, equivalent to about 2.5 mg of imipramine hydrochloride, to a 100-mL volumetric flask, add dilute hydrochloric acid (1 in 100) to volume, and mix. Dissolve an accurately weighed quantity of USP Imipramine Hydrochloride RS in dilute hydrochloric acid (1 in 100), and dilute quantitatively and stepwise with the same solvent to obtain a Standard solution having a known concentration of about 25 µg per mL. Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 250 nm, with a suitable spectrophotometer, using dilute hydrochloric acid (1 in 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 C is the concentration, in µg per mL, of USP Imipramine Hydrochloride RS in the Standard solution; V is the volume, in mL, of the aliquot taken of the solution from the Tablet; and AU and AS are the absorbances of the solution from the Tablet and the Standard solution, respectively.
Assay— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of imipramine hydrochloride, to a 200-mL volumetric flask, add about 100 mL of dilute hydrochloric acid (1 in 25), and shake vigorously by mechanical means for 1 hour. Add the dilute acid to volume, mix, and filter, discarding the first 20 mL of the filtrate. Pipet 5 mL of the filtrate into a separator, and proceed as directed in the Assay under Imipramine Hydrochloride Injection, beginning with “add 10 mL of 1 N sodium 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 C is the concentration, in µg per mL, of USP Imipramine Hydrochloride RS in the Standard solution; and AU and AS are the absorbances of the solution from the Tablets and the Standard solution, respectively.
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