Aspirin Boluses
» Aspirin Boluses contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of aspirin (C9H8O4).
Packaging and storage— Preserve in tight containers.
Labeling— Label Boluses to indicate that they are for veterinary use only.
Identification—
A: Crush 1 Bolus, boil a portion of the powder, equivalent to about 300 mg of aspirin, with 50 mL of water, cool, and add a drop of ferric chloride TS: a violet-red color is produced.
B: The retention time of the aspirin peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Dissolution 711
Medium: 0.5 M phosphate buffer, pH 7.4; 900 mL.
Apparatus 2: 75 rpm.
Time: 45 minutes.
Diluting solution— Prepare a mixture of acetonitrile and formic acid (99:1).
Procedure— Determine the amount of aspirin (C9H8O4) dissolved by employing UV absorption at the wavelength of the isosbestic point of aspirin and salicylic acid at 265 ± 2 nm on filtered portions of the solution under test, suitably diluted with Diluting solution, if necessary, in comparison with a Standard solution having a known concentration of USP Aspirin RS in the same Medium. [note—Prepare the Standard solution at the time of use.]
Tolerances— Not less than 80% (Q) of the labeled amount of C9H8O4 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Limit of salicylic acid— Using the chromatograms of the Standard preparation and the Assay preparation, obtained as directed in the Assay, calculate the percentage of salicylic acid (C7H6O3) in the portion of Boluses taken by the formula:
100,000(C / WA)(rU / rS)
in which C is the concentration, in mg per mL, of USP Salicylic Acid RS in the Standard preparation; WA is the quantity, in mg, of aspirin (C9H8O4) in the portion of Boluses taken, as determined in the Assay; and rU and rS are the salicylic acid peak responses obtained from the Assay preparation and the Standard preparation, respectively: not more than 0.3% is found.
Assay—
Mobile phase— Dissolve 2 g of sodium 1-heptanesulfonate in a mixture of 850 mL of water and 150 mL of acetonitrile, and adjust with glacial acetic acid to a pH of 3.4. Make any necessary adjustments (see System Suitability under Chromatography 621).
Diluting solution— Prepare a mixture of acetonitrile and formic acid (99:1).
Standard preparation— Prepare a solution in Diluting solution having known concentrations of about 0.4 mg of USP Aspirin RS and 0.01 mg of USP Salicylic Acid RS per mL.
Assay preparation— Weigh and finely powder not fewer than 10 Boluses. Transfer an accurately weighed portion of the powder, equivalent to about 400 mg of aspirin, to a 100-mL volumetric flask, dilute with Diluting solution to volume, and stir by mechanical means for about 15 minutes. Pass a portion of this solution through a filter having a 0.5-µm or finer porosity, and use the filtrate as the Assay preparation.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. The flow rate is about 1 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative retention times are about 0.6 for salicylic acid and 1.0 for aspirin, and the relative standard deviation of the aspirin peak response 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 aspirin (C9H8O4) in the portion of Boluses taken by the formula:
1000C(rU / rS)
in which C is the concentration, in mg per mL, of USP Aspirin RS in the Standard preparation; and rU and rS are the aspirin 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 Ian DeVeau, Ph.D.
Director, Veterinary Drugs and Radiopharmaceuticals
1-301-816-8178
(VET05) Veterinary Drugs 05
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
711 Margareth R.C. Marques, Ph.D.
Senior Scientist
1-301-816-8106
(BPC05) Biopharmaceutics05
USP32–NF27 Page 1583
Pharmacopeial Forum: Volume No. 31(4) Page 1026
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.