Sorbitan Monopalmitate

[Graphic formula same as for Sorbitan Monolaurate, except that R is (C15H31)COO.]
Sorbitan, esters, monohexadecanoate.
Sorbitan monopalmitate [26266-57-9].
» Sorbitan Monopalmitate is a partial ester of palmitic acid with Sorbitol and its mono- and dianhydrides. It yields, upon saponification, not less than 63.0 percent and not more than 71.0 percent of fatty acids, and not less than 32.0 percent and not more than 38.0 percent of polyols (w/w).
Packaging and storage— Preserve in well-closed containers.
A: The residue of palmitic acid obtained in the Assay for fatty acids has an acid value (see Fats and Fixed Oils 401) between 210 and 225, about 1 g of the residue, accurately weighed, being used, and an iodine value (see Fats and Fixed Oils 401) of not more than 4.
B: It responds to Identification test B under Sorbitan Monooleate.
Acid value 401: not more than 8.
Hydroxyl value 401: between 275 and 305.
Saponification value 401: between 140 and 150.
Water, Method I 921: not more than 1.5%.
Residue on ignition 281: not more than 0.5%.
Heavy metals, Method II 231: not more than 0.001%.
Assay for fatty acids— Transfer about 10 g of Sorbitan Monopalmitate, accurately weighed, to a 500-mL conical flask, cautiously add 100 mL of alcohol and 3.0 g of potassium hydroxide, and mix. Proceed as directed in the Assay for fatty acids under Sorbitan Monooleate, beginning with “Connect a suitable condenser.”
Assay for polyols— Proceed with Sorbitan Monopalmitate as directed for Assay for polyols under Sorbitan Monooleate.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, B.A.
(EM105) Excipient Monographs 1
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1350
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.