» Mazindol Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of mazindol (C16H13ClN2O).
Packaging and storage Preserve in tight containers, at a temperature not exceeding 25.
USP Reference standards 11
Identification Place a portion of powdered Tablets, equivalent to about 1 mg of mazindol, in a suitable flask. Add 40 mL of methanol, shake by mechanical means for not less than 5 minutes, and heat for several minutes on a steam bath to boiling. Cool, dilute with methanol to about 100 mL, and filter. Separate the filtrate into two approximately equal portions, add 2 drops of hydrochloric acid to one portion, and mix: the UV absorption 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.
Medium: 0.01 N hydrochloric acid; 500 mL.
Apparatus 2: 50 rpm.
Time: 120 minutes.
Determine the amount of C16H13ClN2O dissolved by employing the following method.
Mobile phase Mix 11.50 g of monobasic ammonium phosphate and 1.32 g of dibasic ammonium phosphate with water to obtain 1000 mL of an ammonium phosphate buffer. The Mobile phase is a suitably filtered and degassed mixture of the ammonium phosphate buffer and acetonitrile (55:45). Make adjustments if necessary (see System Suitability under Chromatography 621).
Chromatographic system (see Chromatography 621)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 2 mL per 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 (50 µL to 500 µL) 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 C16H13ClN2O dissolved in comparison with a Standard solution having a known concentration of USP Mazindol RS in the same Medium and similarly chromatographed.
Tolerances Not less than 80% (Q) of the labeled amount of C16H13ClN2O is dissolved in 120 minutes.
Uniformity of dosage units 905: meet the requirements.
procedure for content uniformity
Dye solution Dissolve 100 mg of bromocresol purple in 1000 mL of 0.33 N acetic acid, and mix.
Standard solution Dissolve an accurately weighed quantity of USP Mazindol RS in 0.33 N acetic acid, and dilute quantitatively and stepwise with 0.33 N acetic acid to obtain a solution having a known concentration of about 20 µg per mL.
Test solution Mix 1 finely powdered Tablet with an accurately measured volume of 0.33 N acetic acid, sufficient to provide a solution having a concentration of about 20 µg of mazindol per mL, shake by mechanical means for 30 minutes, and filter, discarding the first few mL of the filtrate.
Procedure Transfer 25.0 mL each of the Standard solution, the Test solution, and 0.33 N acetic acid to provide the blank, to individual 125-mL separators. Add 30 mL of Dye solution and 50.0 mL of chloroform to each, and shake by mechanical means for 15 minutes. Allow the layers to separate, and filter the chloroform layers. Concomitantly determine the absorbances of the filtered solutions obtained from the Test solution and the Standard solution at the wavelength of maximum absorbance at about 420 nm, 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 T is the labeled quantity, in mg, of mazindol in the Tablet; C is the concentration, in µg per mL, of USP Mazindol RS in the Standard solution; D is 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 AU and AS are the absorbances of the solutions from the Test solution and the Standard solution, respectively.
Internal standard solution Dissolve 50 mg of amitriptyline hydrochloride in 250 mL of methanol, and mix.
Standard preparation Transfer about 32 mg of USP Mazindol RS, accurately weighed, to a 100-mL volumetric flask, add about 50 mL of Internal standard solution, and shake by mechanical means for 30 minutes. Dilute with Internal standard solution to volume, and mix.
Assay preparation Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 8 mg of mazindol, to a suitable flask, add 25.0 mL of Internal standard solution, and shake by mechanical means for 30 minutes. Pass through a fine-porosity, sintered-glass filter, discarding the first few mL of the filtrate.
Mobile phase Transfer 200 mL of aqueous 0.01 M dibasic ammonium phosphate to a 1000-mL volumetric 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 621)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 20 µL) of the Standard preparation and the Assay preparation into 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 C is the concentration, in mg per mL, of USP Mazindol RS in the Standard preparation; and RU and RS are the peak response ratios of mazindol to amitriptyline hydrochloride obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 3769