System suitability solution— Dissolve about 45mg of USP Isopropyl Myristate RSand 5mg of USP Isopropyl Palmitate RSin 10.0mLof n-hexane.

Assay preparation— Dissolve 125mg of Isopropyl Myristate 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 90to 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 C17H34O2in the portion of Isopropyl Myristate taken by the formula: in which Ais the isopropyl myristate peak response;and Bis the sum of the responses of all the peaks in the chromatogram,except the solvent peak.