Purified Stearic Acid
» Purified Stearic Acid is manufactured from fats and oils derived from edible sources and is a mixture of Stearic Acid (C18H36O2) and palmitic acid (C16H32O2), which together constitute not less than 96.0 percent of the total content. The content of C18H36O2 is not less than 90.0 percent of the total.
[note—Purified Stearic Acid labeled solely for external use is exempt from the requirement that it be prepared from edible sources. ]
Packaging and storage— Preserve in well-closed containers.
Labeling— If it is for external use only, the labeling so indicates.
USP Reference standards 11
USP Stearic Acid RS Click to View Structure
USP Palmitic Acid RS Click to View Structure
Congealing temperature 651: between 66 and 69.
Acid value 401: between 195 and 200, about 1 g, accurately weighed, being used.
Iodine value 401: not more than 1.5. Proceed as directed in Method I except to use 35 mL of chloroform.
Other requirements— It meets the requirements for Residue on ignition, Heavy metals, Mineral acid, Neutral fat or paraffin, and Assay under Stearic Acid.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
Reference Standards RS Technical Services
USP35–NF30 Page 1992
Pharmacopeial Forum: Volume No. 29(3) Page 706