Mesalamine Rectal Suspension
» Mesalamine Rectal Suspension is a suspension of Mesalamine in a suitable aqueous vehicle. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of mesalamine (C7H7NO3). It contains one or more suitable preservatives.
Packaging and storage— Preserve in tight, light-resistant containers.
USP Reference standards 11—
USP Mesalamine RS Click to View Structure
Identification— 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.
Uniformity of dosage units 905: meets the requirements.
procedure for content uniformity—
Buffer solution, Mobile phase, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under Mesalamine.
Standard solution— Transfer about 100 mg of USP Mesalamine RS, accurately weighed, to a 50-mL volumetric flask, add 15 mL of 2 N hydrochloric acid, and dissolve by swirling. Dilute with 2 N hydrochloric acid to volume, and mix. Transfer 5.0 mL of this solution to a 25-mL volumetric flask, add 5 mL of 2 N sodium hydroxide, dilute with Mobile phase to volume, and mix. Pass this solution through a suitable filter having a 0.5-µm or finer porosity.
Test solution— Transfer, with the aid of 2 N hydrochloric acid, the contents of a container of Rectal Suspension to a 200-mL volumetric flask. Add 2 N hydrochloric acid to obtain about 160 mL of solution, and shake for about 10 minutes. Dilute with 2 N hydrochloric acid to volume, and mix. Transfer an accurately measured volume of this stock solution, equivalent to about 40 mg of mesalamine, to a 100-mL volumetric flask, add a volume of 2 N hydrochloric acid, equal to the added stock solution volume, dilute with Mobile phase to volume, and mix. Pass this solution through a suitable filter having a 0.5-µm or finer porosity.
Procedure— Proceed as directed in the Assay. Calculate the quantity, in g, of C7H7NO3 in the container of Rectal Suspension taken by the formula:
20(C / V)(rU / rS)
in which V is the volume, in mL, of stock solution taken to prepare the Test solution; and the other terms are as defined therein.
pH 791: between 3.5 and 5.5, when diluted 1 to 10 with water.
Related compounds—
Mobile phase, Standard solution, and Chromatographic system— Proceed as directed in Test 1 for Related compounds under Mesalamine.
Test solution— Transfer an accurately measured volume of Rectal Suspension, previously well shaken, equivalent to 100 mg of mesalamine, to a beaker, add water to give a volume of about 80 mL, adjust with phosphoric acid to a pH of 2.0, sonicate briefly to dissolve, transfer to a 100-mL volumetric flask, dilute with water to volume, and mix.
Procedure— Proceed as directed in the test for Related compounds under Mesalamine. Calculate the percentage of each impurity in the Rectal Suspension taken by the formula:
0.1CM(ri / rSM)
in which the terms are as defined therein. Not more than 0.2% of any individual impurity is found; and not more than 1.0% of total impurities is found.
Content of sodium benzoate (if present)—
Mobile phase— Transfer 390 mg of ammonium acetate to a 1000-mL volumetric flask, add 100 mL of water, and dissolve by swirling. Add 6 mL of glacial acetic acid and 300 mL of methanol, dilute with water to volume, and mix. Pass this solution through a filter having a 0.5-µm or finer porosity. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Transfer about 100 mg of sodium benzoate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with water to volume, and mix. Transfer 5.0 mL of this solution to a second 100-mL volumetric flask, add 40 mL of methanol, dilute with water to volume, and mix. Pass this solution through a filter having a 0.5-µm or finer porosity.
Test solution— Transfer about 5 g of well-shaken Rectal Suspension, accurately weighed, to a 100-mL volumetric flask, add 40 mL of methanol, dilute with water to volume, and mix. Pass this solution through a filter having a 0.5-µm or finer porosity.
Chromatographic system— The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 25-cm column that contains packing L7. The flow rate is about 1.5 mL per minute. Inject the Standard solution into the chromatograph, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.5; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 15 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage (w/w) of sodium benzoate in the Rectal Suspension taken by the formula:
10(C / W)(rU / rS)
in which C is the concentration, in mg per mL, of sodium benzoate in the Standard solution; W is the weight, in g, of the Rectal Suspension taken; and rU and rS are the responses obtained from the Test solution and the Standard solution, respectively: it contains between 0.05% and 0.125% of sodium benzoate.
Assay—
Buffer solution, Mobile phase, Resolution solution, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Mesalamine.
Assay preparation— Transfer an accurately measured, well-shaken quantity of Rectal Suspension, equivalent to about 100 mg of mesalamine, to a 100-mL volumetric flask, add 55 mL of Mobile phase, and dissolve by shaking for about 10 minutes. Dilute with Mobile phase to volume, and mix. Transfer 10.0 mL of this solution to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix. Pass this solution through a suitable filter having a 0.5-µm or finer porosity, and use the filtrate as the Assay preparation.
Procedure— Proceed as directed in the Assay under Mesalamine. Calculate the quantity, in mg, of mesalamine (C7H7NO3) in the portion of Rectal Suspension taken by the formula:
250C(rU / rS)
in which the terms are as defined therein.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
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Monograph Clydewyn M. Anthony, Ph.D.
Senior Scientific Liaison
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