» Riboflavin Tablets contain not less than 95.0 percent and not more than 115.0 percent of the labeled amount of C17H20N4O6.
Packaging and storage Preserve in tight, light-resistant containers.
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Time: 45 minutes.
Procedure Determine the amount of C17H20N4O6 dissolved, employing the procedure set forth in the Assay for niacin or niacinamide, pyridoxine hydrochloride, riboflavin, and thiamine, Method 1 under Water-soluble Vitamins Tablets using 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 Riboflavin RS in the same medium.
Tolerances Not less than 75% (Q) of the labeled amount of C17H20N4O6 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Assay Weigh and finely powder not fewer than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 20 mg of riboflavin, transfer to a 250-mL flask, and add 150 mL of 0.1 N hydrochloric acid. Shake vigorously, and wash down the sides of the flask with sufficient 0.1 N hydrochloric acid to ensure that the pH remains below 1.5 during the subsequent period of heating. Heat the mixture on a steam bath, with frequent agitation, until the riboflavin has dissolved, or in an autoclave at 121 for 30 minutes. Cool, adjust the mixture, with vigorous agitation, to a pH of 5 to 6 with 1 N sodium hydroxide, transfer to a 1000-mL volumetric flask, dilute with water to volume, and mix. If the solution is not clear, filter through paper known not to adsorb riboflavin. Dilute an aliquot of the clear solution quantitatively and stepwise with water to make a final measured volume that contains approximately 0.1 µg of riboflavin per mL. Using this as the Assay Preparation, proceed as directed under Riboflavin Assay 481. Calculate the quantity, in mg, of C17H20N4O6 in the portion of powdered Tablets taken by the formula:
200,000C / Win which C is the concentration, in mg per mL, of C17H20N4O6 obtained for the Assay Preparation, and W is the weight, in mg, of powdered Tablets. Calculate the quantity, in mg, of C17H20N4O6 in each Tablet.
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USP32NF27 Page 3498