» Oxaprozin Tablets contain not less than 95.0 percent and not more than 105.0 percent of the labeled amount of oxaprozin (C18H15NO3).
noteBecause of light sensitivity, protect all oxaprozin samples and Standard solutions from light.
Packaging and storage Preserve in tight, light-resistant containers, and store at controlled room temperature.
A: Thin-Layer Chromatographic Identification Test 201
Test solution: 2 mg per mL of oxaprozin in acetone.
Developing solvent system: a mixture of ethyl acetate and glacial acetic acid (99:1).
B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Medium: 0.05 M monobasic potassium phosphate buffer, pH 7.4; 1000 mL.
Apparatus 2: 75 rpm.
Time: 45 minutes.
Procedure Determine the amount of C18H15NO3 dissolved by employing UV absorption at the wavelength of maximum absorbance at about 286 nm on filtered portions of the solution under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Oxaprozin RS in the same Medium (an amount of methanol not exceeding 5% of the final volume can be added to help solubilize the USP Reference Standard).
Tolerances Not less than 75% (Q) of the labeled amount of C18H15NO3 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Water, Method Ia 921: not more than 3.5%.
0.1% Phosphoric acid, pH 2.00 ± 0.10 Add concentrated phosphoric acid, dropwise, to water to obtain a pH of 2.00 ± 0.10.
Mobile phase Prepare a filtered and degassed solution of 0.1% Phosphoric acid, pH 2.00 ± 0.10 and acetonitrile (55:45).
Standard preparation Dissolve an accurately weighed quantity of USP Oxaprozin RS in acetonitrile to obtain a solution having a concentration of about 12 µg of oxaprozin per mL.
Assay stock preparation Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 60 mg of oxaprozin, to a 100-mL volumetric flask, add about 10 mL of water, and sonicate for 10 minutes. Add about 40 mL of acetonitrile, sonicate for 30 minutes, shake by mechanical means for an additional 30 minutes, add about 30 mL of acetonitrile, and sonicate for 10 minutes. Dilute with acetonitrile to volume.
Assay preparation Quantitatively dilute the Assay stock preparation with acetonitrile to obtain a solution having a concentration of about 12 µg of oxaprozin per mL.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 285-nm detector and a 4.6-mm × 15-cm column that contains 5-µm packing L7. The flow rate is about 1.0 mL per minute. Chromatograph the Standard preparation, 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 2.0%.
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 responses for the major peaks. Calculate the quantity, in mg, of oxaprozin (C18H15NO3) in the portion of Tablets taken by the formula:
100C(rU / rS)in which C is the concentration in mg per mL of USP Oxaprozin 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.Chromatographic Column
USP32NF27 Page 3153Pharmacopeial Forum: Volume No. 32(1) Page 130
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.