Benztropine Mesylate Tablets
» Benztropine Mesylate Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C21H25NO·CH4O3S.
Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11—
USP Benztropine Mesylate RS Click to View Structure
Identification— Dissolve about 10 mg of USP Benztropine Mesylate RS in 50 mL of water in a separator to obtain a solution containing about 0.2 mg per mL. Transfer a portion of finely powdered Tablets, equivalent to about 10 mg of benztropine mesylate, to a suitable flask, add 50 mL of water, shake by mechanical means for 30 minutes, and filter into a second separator. Proceed as directed in the Identification test under Benztropine Mesylate Injection, beginning with “Separately add 2 mL of 1 N sodium hydroxide.”
Dissolution 711—
Medium: 0.1 N hydrochloric acid; 900 mL.
Apparatus 2: 50 rpm.
Time: 30 minutes.
Determine the amount of C21H25NO·CH4O3S dissolved by employing the following method.
Octylamine buffer— Proceed as directed in the Assay.
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile and Octylamine buffer (13:7). Make adjustments if necessary (see System Suitability under Chromatography 621).
Test solution— Use a filtered portion of the solution under test from the dissolution vessel.
Standard solution— Dissolve an accurately weighed amount of USP Benztropine Mesylate RS in Dissolution Medium, and dilute quantitatively, and stepwise if necessary, with Dissolution Medium to obtain a solution having a known concentration similar to that of the Test solution.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 220-nm detector and a 4.6-mm × 25-cm column that contains packing L7. The flow rate is about 2 mL per minute. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0; and the relative standard deviation for replicate injections is not more than 3.0%.
Procedure— Separately inject equal volumes (about 300 µL) of the Standard solution and a filtered portion of the solution under test into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C21H25NO·CH4O3S dissolved by the formula:
900C(rU / rS)
in which C is the concentration, in mg per mL, of USP Benztropine Mesylate RS in the Standard solution; and rU and rS are the peak responses obtained from the solution under test and the Standard solution, respectively.
Tolerances— Not less than 80% (Q) of the labeled amount of C21H25NO·CH4O3S is dissolved in 30 minutes.
Uniformity of dosage units 905: meet the requirements.
Assay—
Octylamine buffer— Transfer about 0.83 mL of octylamine to a 1-L volumetric flask, dilute with water to volume, mix, and adjust with phosphoric acid to a pH of 3.0.
Diluting solution— Prepare a mixture of water, isopropyl alcohol, and phosphoric acid (60:40:0.1).
Mobile phase— Prepare a filtered and degassed mixture of Octylamine buffer and acetonitrile (11:9). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Dissolve an accurately weighed quantity of USP Benztropine Mesylate RS in Diluting solution, and dilute quantitatively, and stepwise if necessary, with Diluting solution to obtain a solution having a known concentration of about 0.04 mg per mL.
Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 10 mg of benztropine mesylate, to a 250-mL volumetric flask, and add 150 mL of Diluting solution. Mix by mechanical means for not less than 60 minutes, and dilute with Diluting solution to volume. Centrifuge a portion of this mixture, and filter the supernatant layer.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 259-nm detector and a 4.6-mm × 25-cm column that contains packing L7. The flow rate is about 0.7 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is not more than 4.0; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 50 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of benztropine mesylate (C21H25NO·CH4O3S) in the portion of Tablets taken by the formula:
250C(rU / rS)
in which C is the concentration, in mg per mL, of USP Benztropine Mesylate RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ravi Ravichandran, Ph.D.
Principal Scientific Liaison
1-301-816-8330		 (SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
1-301-816-8106		 (GCDF2010) General Chapters - Dosage Forms
USP35–NF30 Page 2331
Pharmacopeial Forum: Volume No. 28(5) Page 1392