Mazindol Tablets
»Mazindol Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of mazindol (C16H13ClN2O).
Packaging and storage— Preserve in tight containers,at a temperature not exceeding 25.
Identification— Place a portion of powdered Tablets,equivalent to about 1mg of mazindol,in a suitable flask.Add 40mLof methanol,shake by mechanical means for not less than 5minutes,and heat for several minutes on a steam bath to boiling.Cool,dilute with methanol to about 100mL,and filter.Separate the filtrate into two approximately equal portions,add 2drops of hydrochloric acid to one portion,and mix:the UVabsorption spectra of the solutions so obtained exhibit maxima and minima at the same wavelengths as those of similar solutions prepared from USP Mazindol RS,concomitantly measured.
Dissolution á711ñ—
Medium: 0.01Nhydrochloric acid;500mL.
Apparatus 2: 50rpm.
Time: 120minutes.
Determine the amount of C16H13ClN2Odissolved by employing the following method.
Mobile phase— Mix 11.50g of monobasic ammonium phosphate and 1.32g of dibasic ammonium phosphate with water to obtain 1000mLof an ammonium phosphate buffer.The Mobile phaseis a suitably filtered and degassed mixture of the ammonium phosphate buffer and acetonitrile (55:45).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 271-nm detector and a 4-mm ×30-cm column that contains packing L7.The flow rate is about 2mLper minute.Chromatograph three replicate injections of the Standard solution,and record the peak responses as directed for Procedure:the relative standard deviation is not more than 3.0%.
Procedure— Inject an appropriate volume (50µLto 500µL)of a filtered portion of the solution under test into the chromatograph,record the chromatogram,and measure the response for the major peak.Calculate the quantity of C16H13ClN2Odissolved in comparison with a Standard solution having a known concentration of USP Mazindol RSin the same Mediumand similarly chromatographed.
Tolerances— Not less than 80%(Q)of the labeled amount of C16H13ClN2Ois dissolved in 120minutes.
Uniformity of dosage units á905ñ: meet the requirements.
PROCEDURE FOR CONTENT UNIFORMITY—
Dye solution— Dissolve 100mg of bromocresol purple in 1000mLof 0.33Nacetic acid,and mix.
Standard solution— Dissolve an accurately weighed quantity of USP Mazindol RSin 0.33Nacetic acid,and dilute quantitatively and stepwise with 0.33Nacetic acid to obtain a solution having a known concentration of about 20µg per mL.
Test solution— Mix 1finely powdered Tablet with an accurately measured volume of 0.33Nacetic acid,sufficient to provide a solution having a concentration of about 20µg of mazindol per mL,shake by mechanical means for 30minutes,and filter,discarding the first few mLof the filtrate.
Procedure— Transfer 25.0mLeach of the Standard solution,the Test solution,and 0.33Nacetic acid to provide the blank,to individual 125-mLseparators.Add 30mLof Dye solutionand 50.0mLof chloroform to each,and shake by mechanical means for 15minutes.Allow the layers to separate,and filter the chloroform layers.Concomitantly determine the absorbances of the filtered solutions obtained from the Test solutionand the Standard solutionat the wavelength of maximum absorbance at about 420nm,using the blank to set the instrument.Calculate the quantity,in mg,of mazindol (C16H13ClN2O)in the Tablet by the formula:
(TC/D)(AU/AS),
in which Tis the labeled quantity,in mg,of mazindol in the Tablet;Cis the concentration,in µg per mL,of USP Mazindol RSin the Standard solution;Dis the concentration,in µg per mL,of mazindol in the Test solution,based on the labeled quantity per Tablet and the extent of dilution;and AUand ASare the absorbances of the solutions from the Test solutionand the Standard solution,respectively.
Assay—
Internal standard solution— Dissolve 50mg of amitriptyline hydrochloride in 250mLof methanol,and mix.
Standard preparation— Transfer about 32mg of USP Mazindol RS,accurately weighed,to a 100-mLvolumetric flask,add about 50mLof Internal standard solution,and shake by mechanical means for 30minutes.Dilute with Internal standard solutionto volume,and mix.
Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 8mg of mazindol,to a suitable flask,add 25.0mLof Internal standard solution,and shake by mechanical means for 30minutes.Pass through a fine-porosity,sintered-glass filter,discarding the first few mLof the filtrate.
Mobile phase— Transfer 200mLof aqueous 0.01Mdibasic ammonium phosphate to a 1000-mLvolumetric flask,dilute with methanol to volume,and mix.Pass through a 0.5-µm porosity polytef filter,and degas under vacuum.Protect this solution from light.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 4-mm ×30-cm column that contains packing L10.Inject three replicate portions of the Standard preparation,and record the peak responses as directed for Procedure:the resolution,R,is not less than 2.0:and the relative standard deviation is not more than 3.0%.
Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the peak responses for mazindol and amitriptyline hydrochloride.Calculate the quantity,in mg,of mazindol (C16H13ClN2O)in the portion of Tablets taken by the formula:
25C(RU/RS),
in which Cis the concentration,in mg per mL,of USP Mazindol RSin the Standard preparation;and RUand RSare the peak response ratios of mazindol to amitriptyline hydrochloride obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(PA2)Pharmaceutical Analysis 2
USP28–NF23Page 1186
Phone Number:1-301-816-8143