Chlorambucil Tablets
»Chlorambucil Tablets contain not less than 85.0percent and not more than 110.0percent of the labeled amount of C14H19Cl2NO2.
Packaging and storage— Preserve coated Tablets in well-closed containers;preserve uncoated Tablets in well-closed,light-resistant containers.
Identification— Shake a quantity of finely powdered Tablets,equivalent to about 16mg of chlorambucil,with 20mLof carbon disulfide.Filter,evaporate to dryness,and dissolve the residue in 2mLof carbon disulfide:the resulting solution responds to Identificationtest Aunder Chlorambucil.
Disintegration á701ñ— Place 1Tablet in each of the six tubes of the basket,and if the Tablet has a soluble external coating,immerse the basket in water at room temperature for 5minutes.Operate the apparatus,using simulated gastric fluid TSmaintained at 37±2as the immersion fluid.After 30minutes of operation in simulated gastric fluid TS,lift the basket from the fluid,and observe the Tablets.If the Tablets have not disintegrated completely,substitute simulated intestinal fluid TSmaintained at 37±2as the immersion fluid,and continue the test for a total period of time,including previous exposure to water and simulated gastric fluid TS,equal to 45minutes.Lift the basket from the fluid,and observe the Tablets:all of the Tablets have disintegrated completely.If 1or 2Tablets fail to disintegrate completely,repeat the test on 12additional Tablets:not less than 16of the total of 18Tablets tested disintegrate completely.
Uniformity of dosage units á905ñ: meet the requirements.
Assay—
Internal standard solution— Transfer about 20mg of USP Propylparaben RSto a 50-mLvolumetric flask,dissolve in and dilute with alcohol to volume,and mix.
Standard preparation— Dissolve in alcohol a suitable quantity of USP Chlorambucil RS,accurately weighed,and prepare,by quantitative dilution,a solution in alcohol having a known concentration of about 1mg per mL.Transfer 2.0mLof the solution to a 100-mLvolumetric flask containing about 50mLof alcohol and,while gently swirling,add 5.0mLof 0.1Nhydrochloric acid and 2.0mLof Internal standard solution.Dilute with alcohol to volume,and mix.
Assay preparation— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 2mg of chlorambucil,to a 100-mLvolumetric flask containing about 50mLof alcohol and,while gently swirling,add 5.0mLof 0.1Nhydrochloric acid and 2.0mLof Internal standard solution.Sonicate for 5minutes,dilute with alcohol to volume,and mix.Filter through a medium-porosity,sintered-glass filtering funnel,maintaining reduced pressure for the minimum necessary time in order to avoid solvent loss of evaporation.
Mobile phase— Mix 500mLof alcohol with 1.0mLof glacial acetic acid in a 1-liter volumetric flask,dilute with water to volume,and mix.The alcohol concentration may be varied to meet system suitability requirements and to provide a suitable elution time for chlorambucil.Degas the solution at a pressure of approximately 250mm of mercury for 2minutes.
Chromatographic system— Typically,a high-pressure liquid chromatograph,operated at room temperature,is fitted with a 25-or 30-cm ×2-mm stainless steel column packed with spherical silica microbeads,5µm to 10µm in diameter,to which is bonded a nominal 10%or 20%(w/w)octadecyl silane.The mobile phase is maintained at a flow rate capable of giving the required resolution (see System suitability test)and a suitable elution time.An UVdetector that monitors absorption at the 254-nm wavelength is used.
System suitability test— Chromatograph 6to 10injections of the Standard preparation,and measure the peak responses as directed under Procedure.Calculate the response factor,PS,and the resolution factor,R(see Chromatography á621ñ).The response factor for 6to 8injections does not vary by more than 2.0%relative standard deviation and the resolution factor is not less than 2.0.
Procedure— Introduce equal volumes (10to 12µL)of the Standard preparationand the Assay preparationinto the high-pressure liquid chromatograph by means of a suitable sampling valve or high-pressure microsyringe,and measure the peak responses at identical retention times obtained with each preparation.Calculate the quantity,in mg,of C14H19Cl2NO2in the portion of Tablets taken by the formula:
0.1C(PU/PS),
in which Cis the concentration,in µg per mL,of USP Chlorambucil RSin the Standard preparation,and PUand PSare the response factors of the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 426
Phone Number:1-301-816-8389