A:Ultraviolet Absorption á197Uñ—

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

Medium: 0.1Nhydrochloric acid;900mL.

Apparatus 2: 50rpm.

Time: 30minutes.

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

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

Procedure— Transfer 10.0mLof a filtered portion of the solution under test to a 250-mLvolumetric flask,dilute with 0.1Nsodium hydroxide to volume,and mix.Concomitantly determine the absorbances of this solution and the Standard solutionat the wavelengths of maximum and minimum absorbance at about 308nm and 350nm,using 0.1Nsodium hydroxide as the blank.Calculate the quantity,in mg,of C12H15N3O2Sdissolved by the formula: in which Cis the concentration,in µg per mL,of USP Albendazole RSin the Standard solution;and AUand ASare the differences in absorbance between 308nm and 350nm obtained from the solution under test and the Standard solution,respectively.

Tolerances— Not less than 80%(Q)of the labeled amount of C12H15N3O2Sis dissolved in 30minutes.

Procedure for content uniformity—

Acidified methanoland Standard solution— Prepare as directed under Dissolution.

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

Procedure— Concomitantly determine the absorbances of the Standard solutionand the Test solutionat the wavelengths of maximum and minimum absorbance at about 308nm and 350nm,using 0.1Nsodium hydroxide as the blank.Calculate the quantity,in mg,of C12H15N3O2Sin the Tablet taken by the formula: in which Cis the concentration,in µg per mL,of USP Albendazole RSin the Standard preparation;and AUand ASare the differences in absorbance between 308nm and 350nm obtained from the Test solutionand the Standard solution,respectively.

Mobile phase— Dissolve 0.50g of monobasic ammonium phosphate in 400mLof water.Add 600mLof methanol,mix,and filter,discarding the first 15mLof the filtrate.Degas the clear filtrate before use.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

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

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

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

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

Chromatographic system(see Chromatography á621ñ)— 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 2mLper 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 1000theoretical 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 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C12H15N3O2Sin the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Albendazole RSin the Standard preparation;and RUand RSare the peak response ratios of the albendazole peak to the parbendazole peak obtained from the Assay preparationand the Standard preparation,respectively.