ABSTRACT
OBJECTIVE:To establish a method for simultaneous determination of ethinylestradiol and norelgestromin in hor-monal patches. METHODS:RP-HPLC method was performed on column of WondaCract ODS-2 with mobile phase of metha-nol-0.5% phosphoric acid(68∶32,V/V)at a flow rate of 1.0 ml/min,the detection wavelength was 220 nm,the detection tempera-ture was 25 ℃,and sample volume was 20 μl. RESULTS:The linear relationship was 0.872-130.8 μg/ml for ethinylestradiol(r=0.999 6) and 0.880-132.0 μg/ml for norelgestromin (r=0.999 7);RSDs of precision,reproducibility and stability tests were no more than 1.03%,average recoveries were resectively 101.50%(RSD=0.99%,n=9) and 101.68%(RSD=0.95%,n=9). CON-CLUSIONS:The established method is simple and accurate,and can be used for the content determination of ethinylestradiol and norelgestromin in hormonal patches.