Oxazepam Tablets
» Oxazepam Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C15H11ClN2O2.
Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11
USP Oxazepam RS Click to View Structure
Identification— The solution prepared for measurement of absorbance in the Assay exhibits a maximum at 229 ± 2 nm.
Dissolution 711
Medium: 0.1 N hydrochloric acid; 1000 mL.
Apparatus 2: 50 rpm.
Time: 60 minutes.
Chromatographic system— The liquid chromatograph is fitted with a 232-nm detector and a 4-mm × 30-cm column that contains packing L7. The mobile phase is a degassed mixture of methanol, water, and glacial acetic acid (60:40:1), and the flow rate is about 2 mL per minute. In a suitable system, the relative standard deviation observed following replicate injections is not more than 3.0%.
Procedure— Inject an accurately measured volume (about 10 µL) of a filtered portion of the solution under test into the chromatograph by means of a microsyringe or a sampling valve, record the chromatogram, and measure the response for the major peak. Calculate the quantity of C15H11ClN2O2 dissolved in comparison with a similarly chromatographed Standard solution having a known concentration of USP Oxazepam RS in 0.1 N hydrochloric acid. [note—A volume of alcohol not exceeding 10% of the final total volume of the Standard solution may be used to dissolve the Reference Standard. ]
Tolerances— Not less than 80% (Q) of the labeled amount of C15H11ClN2O2 is dissolved in 60 minutes.
Uniformity of dosage units 905: meet the requirements.
Assay— Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 50 mg of oxazepam, to a medium-porosity, sintered-glass funnel that is fitted into a small suction flask. Add 25 mL of alcohol, mix with the aid of a stirring rod, and after about 5 minutes apply gentle suction to remove the extract. Repeat the extraction with four additional 25-mL portions of alcohol, transfer the extracts to a 250-mL volumetric flask, dilute with alcohol to volume, and mix. Transfer 2.0 mL of this solution to a 100-mL volumetric flask, dilute with alcohol to volume, and mix. Concomitantly determine the absorbances of this solution and of a Standard solution of USP Oxazepam RS in the same medium having a known concentration of about 4 µg per mL in 1-cm cells at the wavelength of maximum absorbance at about 229 nm, with a suitable spectrophotometer, using alcohol as the blank. Calculate the quantity, in mg, of C15H11ClN2O2 in the portion of Tablets taken by the formula:
12.5C(AU / AS)
in which C is the concentration, in µg per mL, of USP Oxazepam 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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Topic/Question Contact Expert Committee
Monograph Hariram Ramanathan, M.S.
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711 Margareth R.C. Marques, Ph.D.
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(GCDF2010) General Chapters - Dosage Forms
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