Dissolution á711ñ
Medium:
pH4.5acetate buffer;900mL.
Apparatus 2:
50rpm.
Time:
30minutes.
Determine the amount of C29H32O13dissolved by employing the following method.
Buffer solution
Dissolve 5.44g of sodium acetate in 2000mLof water,adjust with acetic acid to a pHof 4.0,and filter.
Mobile phase
Prepare a filtered and degassed mixture of
Buffer solution and acetonitrile (74:26).Make adjustments if necessary (see
System Suitability under
Chromatography á621ñ).
Standard solution
Dissolve,with sonication,an accurately weighed quantity of
USP Etoposide RSin a volume of methanol equivalent to 2%of the final solution volume.Dilute with
Dissolution Medium to obtain a solution having a known concentration of about 55µg per mL,and mix.
Test solution
At 30minutes withdraw a 10-mLaliquot from the dissolution vessel.
Chromatographic system
The liquid chromatograph is equipped with a 240-nm detector and a 3.9-mm ×30-cm column that contains packing L11.The flow rate is about 2mLper minute.Chromatograph theStandard solution,and record the peak responses as directed forProcedure:the relative standard deviation for replicate injections is not more than 2.0%.
Procedure
Separately inject equal volumes (about 50µL)of the filtered portions of theStandard solution and theTest solution into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Determine the amount of C29H32O13dissolved.
Tolerances
Not less than 80%(Q)of the labeled amount of C29H32O13is dissolved in 30minutes.
Assay
Buffer solution,Mobile phase,Standard preparation,System suitability solution,and Chromatographic system
Proceed as directed in theAssay underEtoposide.
Assay preparation
Transfer an accurately counted number of Capsules,equivalent to about 500mg of etoposide,to a 500-mLvolumetric flask,add about 400mLofMobile phase,and stir using a magnetic bar for about 15minutes,followed by sonication for about 1hour with occasional shaking.Cool,dilute withMobile phase to volume,stir for an additional 5minutes,and filter.Transfer 10.0mLof this solution to a 50-mLvolumetric flask,dilute withMobile phase to volume,and mix.
Procedure
Proceed as directed in the
Assay under
Etoposide.Calculate the quantity,in mg,of etoposide (C
29H
32O
13)per Capsule by the formula:
2500(C/N)(rU/rS),
in which
Cis the concentration,in mg per mL,of
USP Etoposide RSin the
Standard preparation;Nis the number of Capsules taken;and
rUand
rSare the etoposide peak responses obtained from the
Assay preparation and the
Standard preparation,respectively.