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Sorbitan Monostearate
[Graphic formula same as for Sorbitan Monolaurate,except that Ris (C17H35)COO.] Sorbitan,esters,monooctadecanoate. Sorbitan monostearate [1338-41-6]. »Sorbitan Monostearate is a partial ester of Stearic Acid with Sorbitol and its mono-and dianhydrides.It yields,upon saponification,not less than 68.0percent and not more than 76.0percent of fatty acids,and not less than 27.0percent and not more than 34.0percent of polyols (w/w).
Packaging and storage—
Preserve in well-closed containers.
Identification—
A:
The residue of stearic acid obtained in the Assay for fatty acidshas an acid value (see Fats á401ñ)between 200and 215,about 1g of the residue,accurately weighed,being used,and an iodine value (see Fats and Fixed Oils á401ñ)of not more than 4.
Acid value á401ñ:
not more than 10.
Hydroxyl value á401ñ:
between 235and 260.
Saponification value á401ñ:
between 147and 157.
Water,Method Iá921ñ:
not more than 1.5%.
Residue on ignition á281ñ:
not more than 0.5%.
Heavy metals,Method IIá231ñ:
not more than 0.001%.
Organic volatile impurities,Method IVá467ñ:
meets the requirements.
Assay for fatty acids—
Transfer about 10g of Sorbitan Monostearate,accurately weighed,to a 500-mLconical flask,cautiously add 100mLof alcohol and 3.0g of potassium hydroxide,and mix.Proceed as directed in the Assay for fatty acidsunder Sorbitan Monooleate,beginning with “Connect a suitable condenser.”
Assay for polyols—
Proceed with Sorbitan Monostearate as directed for Assay for polyolsunder Sorbitan Monooleate.
Auxiliary Information—
Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3084
Phone Number:1-301-816-8330
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