A: The RFvalue of the principal spot observed in the chromatogram of the Test preparationcorresponds to that of the Standard preparationin the test for Chromatographic purity.

B: The UVabsorption spectrum of the Assay preparation,prepared as directed in the Assay,exhibits maxima and minima at the same wavelengths as that of a similar solution of USP Clofazimine RS,concomitantly measured.

Medium: water;500mL.

Apparatus 2: 50rpm.

Time: 15minutes.

Procedure— Place 1Capsule in each vessel,and allow the Capsule to sink to the bottom of the vessel before starting rotation of the blade.Observe the Capsules,and record the time taken for each capsule shell to rupture.

Tolerances— The requirements are met if all of the Capsules tested rupture in not more than 15minutes.If 1or 2of the Capsules rupture in more than 15but not more than 30minutes,repeat the test on 12additional Capsules.Not more than 2of the total of 18Capsules tested rupture in more than 15but not more than 30minutes.

Ammonia solution,Chromatographic plate,and Procedure— Proceed as directed in the test for Chromatographic purityunder Clofazimine.

Standard preparations— Dissolve an accurately weighed quantity of USP Clofazimine RSin methylene chloride,and mix to obtain Standard preparation Ahaving a known concentration of about 0.5mg per mL.Dilute portions of Standard preparation Aquantitatively with methylene chloride to obtain Standard preparations Band Chaving known concentrations of 0.1and 0.04mg per mL,respectively.

Test preparation— To a portion of Capsule contents,equivalent to about 500mg of clofazimine,add 25mLof methylene chloride and 25mLof 0.1Nsodium hydroxide,and sonicate for 30minutes.Withdraw the methylene chloride layer,and filter through anhydrous sodium sulfate.

0.1N Methanolic hydrochloric acid— Pipet 10mLof hydrochloric acid into a 1000-mLvolumetric flask containing about 500mLof methanol,mix,and dilute with methanol to volume.

Reference solution— Pipet 5mLof methylene chloride into a 50-mLvolumetric flask,dilute with 0.1N Methanolic hydrochloric acidto volume,and mix.

Standard preparation— Dissolve an accurately weighed quantity of USP Clofazimine RSin methylene chloride,and dilute quantitatively,and stepwise if necessary,with methylene chloride to obtain a solution having a known concentration of about 0.075mg per mL.Transfer 5.0mLof this solution to a 50-mLvolumetric flask,dilute with 0.1N Methanolic hydrochloric acidto volume,and mix.

Assay preparation— Remove,as completely as possible,the contents of not less than 20Capsules with the aid of methylene chloride.Dissolve in methylene chloride,filter the solution through a pledget of cotton,and dilute quantitatively,and stepwise if necessary,with methylene chloride to obtain a solution having a concentration of about 0.075mg per mL.Transfer 5.0mLof this solution to a 50-mLvolumetric flask,dilute with 0.1N Methanolic hydrochloric acidto volume,and mix.

Procedure— Concomitantly determine the UVabsorbances of the Standard preparationand the Assay preparationat the wavelength of maximum absorbance at about 491nm,using the Reference solutionas the blank.Calculate the quantity,in mg,of C27H22Cl2N4in the Capsules taken by the formula: in which Lis the labeled quantity,in mg,of clofazimine in each Capsule;Dis the concentration,in mg per mL,of clofazimine in the Assay preparation,based on the labeled quantity and extent of dilution;Cis the concentration,in mg per mL,of USP Clofazimine RSin the Standard preparation;and AUand ASare the absorbances of the Assay preparationand the Standard preparation,respectively.