Stearoyl Polyoxylglycerides
(Title for this new monograph—to become official April 1, 2010)
(Prior to April 1, 2010, it is expected that the current practice of labeling the article of commerce with the name Stearoyl Macrogolglycerides will be continued)
» Stearoyl Polyoxylglycerides are mixtures of monoesters, diesters, and triesters of glycerol and monoesters and diesters of polyethylene glycols with a nominal mean relative molecular weight between 300 and 4000. They are produced by partial alcoholysis of saturated oils, mainly containing triglycerides of stearic acid, with polyethylene glycol, by esterification of glycerol and polyethylene glycol with fatty acids, or as a mixture of glycerol esters and ethylene oxide condensate with the fatty acids of the hydrogenated oils. The Hydroxyl Value does not differ by more than 15 units from the nominal value, and the Saponification Value does not differ by more than 10 units from the nominal value. The average molecular weight is not less than 90.0 percent and not more than 110.0 percent of the labeled nominal value.
Packaging and storage— Preserve in tight containers, protected from light and moisture. Store at controlled room temperature.
Labeling— Label it to indicate the average nominal molecular weight of esters as part of the official title. The label also indicates the Hydroxyl Value and the Saponification Value.
Identification—
B: It meets the requirements for Identification test B under Caprylocaproyl Polyoxylglycerides.
Acid value 401: not more than 2.0, determined on a 2.0-g specimen.
Hydroxyl value 401 The Hydroxyl Value, between 25 and 56, does not differ by more than 15 units from the nominal value, determined on a 1.0-g specimen, accurately weighed.
Iodine value 401: not more than 2.0.
Peroxide value 401: not more than 6.0, determined on a 2.0-g specimen.
Saponification value 401 The Saponification Value, between 67 and 112, does not differ by more than 10 units from the nominal value, determined on a 2.0-g specimen.
Fatty acid composition 401: not more than 5.0% each of lauric acid and myristic acid is found; between 40.0% and 50.0% of palmitic acid is found; and between 48.0% and 58.0% of stearic acid is found.
Water, Method I 921: not more than 1.0%, determined on a 1.0-g specimen.
Total ash 561: not more than 0.2%, determined on a 1.0-g specimen.
Limit of free ethylene oxide and dioxane— Proceed as directed in the test for Limit of free ethylene oxide and dioxane under Caprylocaproyl Polyoxylglycerides: not more than 1 µg of ethylene oxide per g is found; and not more than 10 µg of dioxane per g is found.
Limit of free glycerol— Proceed as directed in the test for Limit of free glycerol under Caprylocaproyl Polyoxylglycerides: not more than 5.0% is found.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Hong Wang, Ph.D.
Scientist
1-301-816-8351
(EM205) Excipient Monographs 2
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
USP32–NF27 Page 1361
Pharmacopeial Forum: Volume No. 34(5) Page 1228