Aminosalicylic Acid Tablets
» Aminosalicylic Acid Tablets contain not less than 95.0 percent and not more than 105.0 percent of the labeled amount of aminosalicylic acid (C7H7NO3).
Packaging and storage Preserve in tight, light-resistant containers, at a temperature not exceeding 30.
USP Reference standards 11
Identification Macerate a portion of powdered Tablets, equivalent to about 2 g of aminosalicylic acid, with 50 mL of a mixture of 1 volume of acetone and 2 volumes of chloroform, and filter. Evaporate the filtrate with the aid of a current of warm air to dryness: the residue so obtained responds to Identification tests B and C under Aminosalicylic Acid.
Medium: pH 7.5 phosphate buffer (see Buffer Solutions in the section Reagents, Indicators, and Solutions); 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Procedure Determine the amount of C7H7NO3 dissolved, employing the procedure set forth in the Assay, making any necessary modifications.
Tolerances Not less than 75% (Q) of the labeled amount of C7H7NO3 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Limit of m-aminophenol
Mobile phase and Internal standard solution Prepare as directed in the Assay under Aminosalicylic Acid.
Standard solution and Chromatographic system Prepare as directed in the test for Limit of m-aminophenol under Aminosalicylic Acid.
Test solution Use the Assay preparation, prepared as directed in the Assay.
Procedure Proceed as directed for Procedure in the test for Limit of m-aminophenol under Aminosalicylic Acid. Calculate the percentage of m-aminophenol, in relation to the quantity of aminosalicylic acid in the portion of Tablets taken by the formula:
100(C / W)(RU / RS)in which C is the concentration, in µg per mL, of USP m-Aminophenol RS in the Standard solution; W is the quantity of aminosalicylic acid, in mg, in the portion of Tablets taken, as determined in the Assay; and RU and RS are the ratios of the response of the m-aminophenol peak to the response of the sulfanilamide peak obtained from the Test solution and the Standard solution, respectively: not more than 1.0% of m-aminophenol is found.
Mobile phase, Internal standard solution, Standard preparation, and Chromatographic system Prepare as directed in the Assay under Aminosalicylic Acid.
Assay preparation Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 500 mg of aminosalicylic acid, to a 100-mL low-actinic volumetric flask. Add 50 mL of Mobile phase, and shake for about 5 minutes. Dilute with Mobile phase to volume, and mix. Filter, and transfer 10.0 mL of the clear filtrate to a 100-mL low-actinic volumetric flask containing 10.0 mL of Internal standard solution, dilute with Mobile phase to volume, and mix.
Procedure Proceed as directed for Procedure in the Assay under Aminosalicylic Acid. Calculate the quantity, in mg, of aminosalicylic acid (C7H7NO3) in the portion of Tablets taken by the formula:
1000C(RU / RS)in which C is the concentration, in mg per mL, of USP Aminosalicylic Acid RS in the Standard preparation; and RU and RS are the ratios of the response of the aminosalicylic acid peak to the response of the acetaminophen peak obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2179