Docusate Potassium
;)
Butanedioic acid,sulfo-,1,4-bis(2-ethylhexyl)ester,potassium salt.
Potassium 1,4-bis(2-ethylhexyl)sulfosuccinate [7491-09-0].
»Docusate Potassium contains not less than 95.0percent and not more than 100.5percent of C20H37KO7S,calculated on the dried basis.
Packaging and storage—
Preserve in well-closed containers.
USP Reference standards á11ñ—
USP Docusate Potassium RS.USP Bis(2-ethylhexyl)maleate RS.
Identification—
A:
Place a small piece of it on a salt plate,add 1drop of acetone,and promptly cover with another salt plate.Rub the plates together to dissolve the specimen,slide the plates apart,and allow the acetone to evaporate:the IRabsorption spectrum of the film so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Docusate Potassium RS.
B:
It responds to the flame test for Potassium á191ñ.
Loss on drying á731ñ—
Dry it in a glass container at 105
for 4hours:it loses not more than 3.0%of its weight.
for 4hours:it loses not more than 3.0%of its weight.
Residue on ignition á281ñ:
between 18.0%and 20.0%,calculated on the dried basis.
Limit of bis(2-ethylhexyl)maleate—
Place 12.5g of Docusate Potassium,previously dried and accurately weighed,in a 100-mLvolumetric flask.Pipet 20mLof pH10alkaline borate buffer (see under Solutionsin the section Reagents,Indicators,and Solutions)into the flask,and add about 70mLof alcohol.Swirl the flask and contents,with gentle warming if necessary,until the solid dissolves.Adjust the reaction dropwise,if necessary,with 1Nsodium hydroxide to a pHof 10.Add alcohol to volume,and proceed as directed in the test for Bis(2-ethylhexyl)maleateunder Docusate Sodium,beginning with “Transfer a portion of this solution to a polarographic cell.”The diffusion current for the test solution of Docusate Potassium is not greater than one-half the diffusion current of the solution containing the added bis(2-ethylhexyl)maleate [not more than 0.4%of bis(2-ethylhexyl)maleate].
Assay—
Tetra-n-butylammonium iodide solution,and Salt solution—
Prepare as directed in the Assayunder Docusate Sodium.
Procedure—
Dissolve about 100mg of Docusate Potassium,accurately weighed,in 50mLof chloroform in a glass-stoppered,250-mLconical flask.Proceed as directed in the Assayunder Docusate Sodium,beginning with “Add 50mLof Salt solution.”Each mLof Tetra-n-butylammonium iodide solutionis equivalent to 3.118mg of C20H37KO7S.
Auxiliary Information—
Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 684
Phone Number:1-301-816-8251