Aminobenzoate Potassium Capsules
» Aminobenzoate Potassium Capsules contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of aminobenzoate potassium (C7H6 KNO2).
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
Identification Dissolve about 1 g of the Capsule contents in 25 mL of water, add 5 mL of 3 N hydrochloric acid, and wash the precipitate with two 5-mL portions of cold water. Recrystallize from alcohol the precipitate so obtained, and dry at 110 for 1 hour: the p-aminobenzoic acid so obtained melts between 186 and 189.
Medium: water; 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Procedure Determine the amount of C7H6KNO2 dissolved by employing UV absorption at the wavelength of maximum absorbance at about 270 nm on filtered portions of the solution under test, suitably diluted with Medium, in comparison with a Standard solution having a known concentration of USP Aminobenzoate Potassium RS in the same Medium.
Tolerances Not less than 75% (Q) of the labeled amount of C7H6KNO2 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Standard preparation Prepare a solution of USP Aminobenzoate Potassium RS having a known concentration of about 5 µg per mL.
Assay preparation Remove as completely as possible, and combine, the contents of not fewer than 20 Capsules. Transfer an accurately weighed portion of the combined contents, equivalent to about 100 mg of aminobenzoate potassium, to a 200-mL volumetric flask, add 150 mL of water, shake by mechanical means for 30 minutes, dilute with water to volume, mix, and filter. Pipet 2 mL of the filtrate into a 200-mL volumetric flask, dilute with water to volume, and mix.
Procedure Concomitantly determine the absorbances of the Standard preparation and the Assay preparation at the wavelength of maximum absorbance at about 270 nm, with a suitable spectrophotometer, using water as the blank. Calculate the quantity, in mg, of aminobenzoate potassium (C7H6KNO2) in the portion of Capsule contents taken by the formula:
20C(AU / AS)in which C is the concentration, in µg per mL, of USP Aminobenzoate Potassium RS in the Standard preparation; and AU and AS are the absorbances of the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2165