Maprotiline Hydrochloride Tablets
»Maprotiline Hydrochloride Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of maprotiline hydrochloride (C20H23N·HCl).
Packaging and storage— Preserve in well-closed containers.
Identification—
A: Standard solution—Dissolve 20mg of USP Maprotiline Hydrochloride RSin 1.0mLof methanol.
Test solution— Transfer a portion of powdered Tablets,equivalent to about 100mg of maprotiline hydrochloride,to a glass-stoppered centrifuge tube.Add 5.0mLof methanol to the tube,sonicate for 10minutes,shake by mechanical means for 10minutes,and centrifuge.
Procedure— In a suitable chromatographic chamber (see Chromatography á621ñ),place a volume of a solvent system consisting of a mixture of secondary butyl alcohol,ethyl acetate,and 2Nammonium hydroxide (6:3:1)sufficient to develop a chromatogram.Place a beaker containing 25mLof ammonium hydroxide in the bottom of the chamber,and allow it to equilibrate for 1hour.Apply 5-µLportions of the Test solutionand the Standard solutionto a suitable thin-layer chromatographic plate,coated with a 0.25-mm layer of chromatographic silica gel that has been prewashed with chloroform by allowing chloroform to travel the full length of the plate and dried at 100for 30minutes,and allow the spots to dry.Develop the chromatogram until the solvent front has moved about three-fourths of the length of the plate,remove the plate from the developing chamber,mark the solvent front,and allow the solvent to evaporate.Expose the plate to hydrogen chloride vapor for 30minutes,expose it to a high-intensity UVlight irradiator (1000to 1600watts)[Caution—UVirradiators emit UVradiation that is harmful to eyes and skin. ]for 5minutes,and compare the chromatograms under long-wavelength UVlight:the RFvalue of the principal spot obtained from the Test solutioncorresponds to that obtained from the Standard solution.
B: The retention time of the major peak in the chromatogram of the Assay preparationcorresponds to that of the Standard preparation,as obtained in the Assay.
Dissolution á711ñ—
Medium: dilute hydrochloric acid (7in 1000);900mL.
Apparatus 2: 50rpm.
Time: 60minutes.
Procedure— Determine the amount of C20H23N·HCl dissolved from UVabsorbances,using the difference between the absorbance maximum at about 272nm and the absorbance minimum at about 268nm,of filtered portions of the solution under test,suitably diluted with dilute hydrochloric acid (7in 1000),in comparison with a Standard solution having a known concentration of USP Maprotiline Hydrochloride RSin the sameMedium.
Tolerances— Not less than 75%(Q)of the labeled amount of C20H23N·HCl is dissolved in 60minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay—
Mobile phase— Dissolve 4g of tetramethylammonium chloride in 495mLof water,add 500mLof acetonitrile and 1mLof phosphoric acid,mix,filter,and degas.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation— Transfer an accurately weighed quantity of USP Maprotiline Hydrochloride RSto a suitable volumetric flask,and prepare a solution having a known concentration of about 0.75mg per mLin a mixture of water,methanol,and 0.1Nhydrochloric acid (80:10:10)by sonicating the Reference Standard in the methanol and 0.1Nhydrochloric acid for 5minutes to dissolve,diluting with water to volume,and mixing.
Assay preparation— Transfer not fewer than 15Tablets to a 500-mLvolumetric flask,add 100mLof 0.1Nhydrochloric acid,sonicate,and shake occasionally for 5minutes to disintegrate the Tablets.Add 100mLof methanol,shake,and sonicate for 5minutes.Dilute with water to volume,mix,and centrifuge.Dilute a portion of the supernatant quantitatively,and stepwise if necessary,with water to obtain a solution having a concentration of about 0.75mg per mL.[NOTE—Filtration through commonly available filters may result in unsatisfactory drug adsorption.]
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 272-nm detector and an 8-mm ×10-cm column that contains 10-µm packing L10.The flow rate is about 2.0mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the column efficiency,determined from the analyte peak,is not less than 1500theoretical plates;the tailing factor is not more than 2.0;and the relative standard deviation of the major peak response from replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the areas for the major peaks.Calculate the quantity,in mg,of C20H23N·HCl in the portion of Tablets taken by the formula:
(L/D)C(rU/rS),
in which Lis the labeled amount,in mg,of maprotilene hydrochloride in each Tablet;Dis the concentration,in mg per mL,of maprotilene hydrochloride in the Assay preparation,based on the labeled quantity per Tablet and the extent of dilution;Cis the concentration,in mg per mL,of USP Maprotiline Hydrochloride RSin the Standard preparation;and rUand rSare the maprotilene peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Salvador C.Salado,M.S.,Scientist and Latin American Liaison
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 1185
Phone Number:1-301-816-8165