Colchicine Tablets
»Colchicine Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of C22H25NO6.
Packaging and storage— Preserve in well-closed,light-resistant containers.
Identification— Weigh a portion of ground Tablets,equivalent to about 20mg of colchicine,triturate with 20mLof water,allow the solids to settle,and filter the supernatant into a separator.Extract with 30mLof chloroform.Evaporate the chloroform extract,using mild heat,to dryness:the IRabsorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Colchicine RS.
Dissolution,Procedure for a Pooled Sample á711ñ— [NOTE—Conduct this procedure without delay,under subdued light,and using low-actinic glassware.]
Medium: water;500mL.
Apparatus 1: 100rpm.
Time: 30minutes.
Procedure— Determine the amount of C22H25NO6dissolved,employing the procedure set forth in the Assayunder Colchicine,making any necessary modifications.
Tolerances— Not less than 75%(Q)of the labeled amount of C22H25NO6is dissolved in 30minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay— [NOTE—Perform all dilutions in low-actinic glassware.]
Mobile phase ,Standard preparation,and Chromatographic system—Prepare as directed in the Assay under Colchicine.
Assay preparation— [NOTE—Prepare immediately before use.]Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 0.6mg of colchicine,to a 100-mLvolumetric flask,add about 50mLof a mixture of methanol and water (1:1),and shake by mechanical means for 15minutes,rinsing down the walls of the flask at about 8minutes.Dilute with the same mixture to volume,and pass through a 0.45-µm membrane filter.
Procedure— Proceed as directed for Procedurein the Assayunder Colchicine,and measure the responses for the colchicine peaks.Calculate the quantity,in mg,of C22H25NO6in the portion of Tablets taken by the formula:
0.1C(rU/rS),
in which Cis the concentration,in µg per mL,of the Standard preparation;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist
Expert Committee:(DSB)Dietary Supplements:Botanicals
USP28–NF23Page 538
Pharmacopeial Forum:Volume No.30(1)Page 91
Phone Number:1-301-816-8343