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 C
22H
25NO
6dissolved,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.
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 C
22H
25NO
6in 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.