Glyceryl Monolinoleate
354.5 [26545-74-4].
»Glyceryl Monolinoleate is a mixture of monoglycerides,mainly glyceryl monooleate and glyceryl monolinoleate,together with variable quantities of diglycerides and triglycerides.It is obtained by partial glycerolysis of vegetable oil that consists mainly of triglycerides of linoleic acid.It contains not less than 32.0percent and not more than 52.0percent of monoglycerides,not less than 40.0percent and not more than 55.0percent of diglycerides,and not less than 5.0percent and not more than 20.0percent of triglycerides.Asuitable antioxidant may be added.
Packaging and storage— Preserve in tight containers.Store at room temperature.Protect from light,freezing,and excessive heat.
Labeling— The labeling indicates the name and the concentration of any added antioxidant.
USP Reference standards á11ñ— USP Glyceryl Monolinoleate RS.
Identification—
A: Thin-Layer Chromatographic Identification Test á201ñ—
Test solution: a solution in methylene chloride containing about 0.05µg per mL.
Developing solvent: a mixture of ether and hexane (70:30).
Spray reagent: a solution containing 0.02µg of rhodamine Bin 0.2µLof alcohol.
Procedure— Proceed as directed in the chapter.Spray with the Spray reagent,and locate the spots on the plate by examination under UVlight at a wavelength of 365nm:the principal spot obtained from the Test solutioncorresponds in color,size,and RFvalue to that obtained from the Standard solution.
B: It meets the requirements of the test for Iodine value.
C: It meets the requirements of the test for Fatty acid composition.
Acid value á401ñ: not more than 6.0,determined on 1.0g.
Iodine value á401ñ: between 100and 140.
Peroxide value á401ñ: not more than 12.0,determined on 2.0g.
Saponification value á401ñ: between 160and 180,determined on 2.0g.
Fatty acid composition á401ñ— Glyceryl Monolinoleate exhibits the following composition profile of fatty acids,as determined in the section Fatty Acid Composition:
Carbon-chain
Length		 No.of Double
Bonds		 Percentage (%)
16 0 4.0to 20.0
18 0 not more than 6.0
18 1 10.0to 35.0
18 2 not less than 50.0
18 3 not more than 2.0
20 0 not more than 1.0
20 1 not more than 1.0
Water,Method Iá921ñ: not more than 1.0%,using a mixture of methanol and methylene chloride (1:1,v/v)in place of methanol in the titration vessel.
Total ash á561ñ: not more than 0.1%.
Limit of free glycerin—
Mobile phase and Chromatographic system— Proceed as directed in the Assay.
Standard solutions— Prepare four solutions by dissolving accurately weighed quantities of glycerin in tetrahydrofuran and by diluting each with tetrahydrofuran,as necessary,to obtain solutions having known concentrations of about 0.4,1.0,2.0,and 4.0mg per mL.
Test solution— Use the Assay preparation,prepared as directed in the Assay.
Procedure— Separately inject equal volumes (about 40µL)of the Standard solutionsand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the glycerin peaks.Plot the glycerin peak responses obtained versus the concentration,in mg per mL,of glycerin in the Standard solutions.From the standard curve so obtained,determine the glycerin concentration,C,in mg per mL,in the Test solution.Calculate the percentage of free glycerin in the portion of Glyceryl Monolinoleate taken by the formula:
500(C/W),
in which Cis as obtained above;and Wis the amount,in mg,of Glyceryl Monolinoleate taken to prepare the Test solution:not more than 6.0%of free glycerin is found.
Assay—
Mobile phase: tetrahydrofuran.
Assay preparation— Transfer about 200mg of Glyceryl Monolinoleate,accurately weighed,to a 5-mLvolumetric flask,dissolve in and dilute with tetrahydrofuran to volume,and mix.
Chromatographic system (see Chromatography á621ñ)— Prepare as directed in the Assay under Glyceryl Distearate.Chromatograph the Assay preparation,and record the peak responses as directed for Procedure:the relative retention times are about 1.0for glycerin,0.86for monoglycerides,0.80for diglycerides,and 0.76for triglycerides;the resolution,R,between the diglycerides and monoglycerides is not less than 1.0;and the relative standard deviation for replicate injections determined from the monoglycerides peak is not more than 2.0%.
Procedure— Inject a volume (about 40µL)of the Assay preparation into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the percentage of monoglycerides,diglycerides,and triglycerides in the portion of Glyceryl Monolinoleate taken by the formula:
100(ri/rs),
in which riis the individual peak response for the monoglycerides,diglycerides,and triglycerides,as appropriate;and rsis the sum of the responses for all of the glyceride peaks.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3013
Pharmacopeial Forum:Volume No.30(3)Page 975
Phone Number:1-301-816-8251