A: Ultraviolet Absorption 197U—

B: The retention time of the major peak for albendazole in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

Medium: 0.1 N hydrochloric acid; 900 mL.

Apparatus 2: 50 rpm.

Time: 30 minutes.

Acidified methanol— To about 50 mL of methanol in a 100-mL volumetric flask add 2 mL of hydrochloric acid, dilute with methanol to volume, and mix.

Standard solution— Transfer about 90 mg of USP Albendazole RS, accurately weighed, to a 250-mL volumetric flask, add 10 mL of Acidified methanol, and shake to dissolve. Dilute with 0.1 N hydrochloric acid to volume, and mix. Transfer 5.0 mL of this solution to a 200-mL volumetric flask, dilute with 0.1 N sodium hydroxide to volume, and mix.

Procedure— Transfer 10.0 mL of a filtered portion of the solution under test to a 250-mL volumetric flask, dilute with 0.1 N sodium hydroxide to volume, and mix. Concomitantly determine the absorbances of this solution and the Standard solution at the wavelengths of maximum and minimum absorbance at about 308 nm and 350 nm, using 0.1 N sodium hydroxide as the blank. Calculate the quantity, in mg, of C12H15N3O2S dissolved by the formula: in which C is the concentration, in µg per mL, of USP Albendazole RS in the Standard solution; and AU and AS are the differences in absorbance between 308 nm and 350 nm obtained from the solution under test and the Standard solution, respectively.

Tolerances— Not less than 80% (Q) of the labeled amount of C12H15N3O2S is dissolved in 30 minutes.

Procedure for content uniformity—

Acidified methanol and Standard solution— Prepare as directed under Dissolution.

Test solution— Place 1 Tablet in a 500-mL volumetric flask, add about 300 mL of Acidified methanol, and shake by mechanical means for about 30 minutes. Dilute with Acidified methanol to volume, and mix. Filter a portion of this solution, discarding the first 20 mL of the filtrate. Transfer 4.0 mL of the clear filtrate to a 200-mL volumetric flask, dilute with 0.1 N sodium hydroxide to volume, and mix.

Procedure— Concomitantly determine the absorbances of the Standard solution and the Test solution at the wavelengths of maximum and minimum absorbance at about 308 nm and 350 nm, using 0.1 N sodium hydroxide as the blank. Calculate the quantity, in mg, of C12H15N3O2S in the Tablet taken by the formula: in which C is the concentration, in µg per mL, of USP Albendazole RS in the Standard preparation; and AU and AS are the differences in absorbance between 308 nm and 350 nm obtained from the Test solution and the Standard solution, respectively.

(Official January 1, 2007)

Mobile phase— Dissolve 0.50 g of monobasic ammonium phosphate in 400 mL of water. Add 600 mL of methanol, mix, and filter, discarding the first 15 mL of the filtrate. Degas the clear filtrate before use. Make adjustments if necessary (see System Suitability under Chromatography 621).

Sulfuric acid in methanol— Prepare a mixture of 1 mL of sulfuric acid and 99 mL of methanol.

Internal standard solution— Transfer about 150 mg of USP Parbendazole RS to a 50-mL volumetric flask. Add 5 mL of Sulfuric acid in methanol, 25 mL of methanol, and shake to dissolve. Dilute with methanol to volume, and mix.

Standard preparation— Transfer about 100 mg of USP Albendazole RS, accurately weighed, to a 50-mL volumetric flask. Add 5 mL of Sulfuric acid in methanol and 25 mL of methanol, and shake to dissolve. Dilute with methanol to volume, and mix. Transfer 5.0 mL of this stock solution and 5.0 mL of Internal standard solution to a second 50-mL volumetric flask, dilute with methanol to volume, and mix.

Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of albendazole, to a 50-mL volumetric flask. Add 5 mL of Sulfuric acid in methanol and 20 mL of methanol, and shake by mechanical means for about 15 minutes. Dilute with methanol to volume, mix, and filter, discarding the first 15 mL of the filtrate. Transfer 5.0 mL of the clear filtrate and 5.0 mL of Internal standard solution to a second 50-mL volumetric flask, dilute with methanol to volume, and mix.

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 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0; the column efficiency is not less than 1000 theoretical plates; the resolution between the albendazole peak and the parbendazole peak is not less than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— [NOTE—Use peak heights where peak responses are indicated.] 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 C12H15N3O2S in the portion of Tablets taken by the formula: in which C is the concentration, in mg per mL, of USP Albendazole RS in the Standard preparation; and RU and RS are the peak response ratios of the albendazole peak to the parbendazole peak obtained from the Assay preparation and the Standard preparation, respectively.