Mono-and Di-glycerides
»Mono-and Di-glycerides is a mixture of glycerol mono-and di-esters,with minor amounts of tri-esters,of fatty acids from edible oils.It contains not less than 40.0percent of monoglycerides.The monoglyceride content is not less than 90.0percent and not more than 110.0percent of the value indicated in the labeling.It may contain suitable stabilizers.
Packaging and storage— Preserve in tight,light-resistant containers.
Labeling— The labeling indicates the monoglyceride content,hydroxyl value,iodine value,saponification value,and name and quantity of any stabilizers.
Acid value á401ñ: not more than 4.
Hydroxyl value á401ñ: not less than 90.0%and not more than 110.0%of the value indicated in the labeling.
Iodine value á401ñ: not less than 90.0%and not more than 110.0%of the value indicated in the labeling.If the value stated in the labeling is less than 10,the Iodine value is not more than 10.
Saponification value á401ñ: not less than 90.0%and not more than 110.0%of the value indicated in the labeling.
Residue on ignition á281ñ: not more than 0.1%.
Organic volatile impurities,Method Vá467ñ: meets the requirements.
Solvent— Use dimethyl sulfoxide.
Limit of free glycerin—
Mobile phase and Chromatographic system— Proceed as described in the Assay for monoglycerides.
Standard solutions— Dissolve an accurately weighed quantity of USP Glycerin RSin tetrahydrofuran,and dilute with tetrahydrofuran,as necessary,to obtain solutions having known concentrations of about 0.5mg per mL,1.0mg per mL2.0mg per mL,and 4.0mg per mL.
Test solution— Use the Assay preparation.
Procedure— Separately inject equal volumes (about 40µL)of each of the Standard solutionsand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the glycerin peaks.Plot the concentration,in mg per mL,of USP Glycerin RSin the Standard solutionsversus the glycerin peak responses obtained.From the standard curve so obtained,determine the glycerin concentration,C,in mg per mL,in the Test solution.Calculate the percentage of glycerin in the portion of Mono-and Di-glycerides taken by the formula:
500(C/W),
in which Cis as obtained above;and Wis the amount,in mg,of Mono-and Di-glycerides taken to prepare the Test solution:not more than 7.0%of free glycerin is found.
Assay for monoglycerides—
Mobile phase— Use filtered and degassed tetrahydrofuran.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Assay preparation— Transfer about 200mg of Mono-and Di-glycerides,accurately weighed,to a 5-mLvolumetric flask,dissolve in and dilute with tetrahydrofuran to volume,and mix.
Chromatographic system (see Chromatography á621ñ)— The liquid chromatograph is equipped with a refractive index detector and a 7-mm ×60-cm column that contains 5-µm packing L21(100Å).The flow rate is about 1mLper minute.The column and detector temperatures are maintained at 40.Chromatograph the Assay preparation,and record the peak responses as directed for Procedure.The order of elution is triglycerides,diglycerides,monoglycerides,and glycerin.The relative standard deviation for replicate injections determined from the monoglycerides peak is not more than 1.0%.
Procedure— Inject a volume (about 40µL)of the Assay preparationinto the chromatograph,record the chromatogram,and measure the responses for the major peaks.Calculate the percentage of monoglycerides in the portion of Mono-and Di-glycerides taken by the formula:
100(rU/rS),
in which rUis the peak response for monoglycerides;and rSis the sum of the responses of all the peaks,except the solvent peak.
Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3039
Pharmacopeial Forum:Volume No.30(4)Page 1330
Phone Number:1-301-816-8379