Isopropyl Palmitate
;)
Hexadecanoic acid,1-methylethyl ester.
Isopropyl palmitate [142-91-6].
»Isopropyl Palmitate consists of esters of isopropyl alcohol and saturated high molecular weight fatty acids.It contains not less than 90.0percent of C19H38O2.
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
The retention time of the major peaks obtained in the Assayis the same as that of the corresponding peaks obtained from the System suitability solutionemployed in the Assay.
Specific gravity á841ñ:
between 0.850and 0.855.
Acid value á401ñ:
not more than 1.
Iodine value á401ñ:
not more than 1.
Saponification value á401ñ:
between 183and 193.
Refractive index á831ñ:
between 1.435and 1.438.
Residue on ignition á281ñ:
not more than 0.1%.
Organic volatile impurities,Method IVá467ñ:
meets the requirements.
Assay—
System suitability solution—
Dissolve about 45mg of USP Isopropyl Palmitate RSand 5mg of USP Isopropyl Myristate RSin 10.0mLof n-hexane.
Assay preparation—
Dissolve 125mg of Isopropyl Palmitate in 25.0mLof n-hexane,and mix.
Chromatographic system (see Chromatography á621ñ)—
The gas chromatograph is equipped with a flame-ionization detector and a 4-mm ×1.8-m column packed with 10%liquid phase G8on 100-to 120-mesh support S1A.The carrier gas is nitrogen,flowing at a rate of 45mLper minute.The column temperature is programmed to rise from 90
to 210at a rate of 2per minute and then to maintain at 210for 8minutes.The detector temperature is maintained at 280,and the injection port temperature is maintained at 240.Chromatograph the System suitability solution,and record the peak responses as directed for Procedure:the relative retention times for isopropyl myristate and isopropyl palmitate are about 1and 1.3,respectively;the resolution,R,is not less than 6.0between the peaks due to isopropyl myristate and isopropyl palmitate;the tailing factor for the isopropyl palmitate peak is not more than 2;and the relative standard deviation for replicate injections is not more than 2.0%.
to 210at a rate of 2per minute and then to maintain at 210for 8minutes.The detector temperature is maintained at 280,and the injection port temperature is maintained at 240.Chromatograph the System suitability solution,and record the peak responses as directed for Procedure:the relative retention times for isopropyl myristate and isopropyl palmitate are about 1and 1.3,respectively;the resolution,R,is not less than 6.0between the peaks due to isopropyl myristate and isopropyl palmitate;the tailing factor for the isopropyl palmitate peak is not more than 2;and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Inject about 5µLof the Assay preparationinto the chromatograph,record the chromatogram,and measure the responses for the major peaks.Calculate the percentage of C19H38O2in the portion of Isopropyl Palmitate taken by the formula:
100A/B,
in which Ais the isopropyl palmitate peak response;and Bis the sum of the responses of all the peaks in the chromatogram,except the solvent peak.
Auxiliary Information—
Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3022
Phone Number:1-301-816-8262