Simultaneous Determination of Minoxidil and Tretinoin in Compound Minoxidil Gel by HPLC / 中国药师

ABSTRACT

Objective:To establish an HPLC method for the simultaneous determination of minoxidil and tretinoin in compound minoxidil gel. Methods:A Shim-Pack VP-ODS C18(250 mm × 4. 6 mm,5 μm)column was used with the mobile phase of methanol and 2% acetic acid solution by gradient eleution . The detection wavelength was respectively set at 280 nm and 350 nm,and the flow rate was 1. 0 ml·min -1 . The column temperature was 35℃ and the injection volume was 10 μl. Results:Minoxidil and tretinoin had a good linear relationship within the range of 4. 0- 240. 0 μg·ml-1 and 0. 05- 3. 00 μg·ml-1(r =0. 999 6 and 0. 999 3),respectively. The average recovery was 99. 56%(RSD = 0. 42% ,n = 9)and 99. 36%(RSD = 0. 50% , n = 9),respectively. Conclusion:The established method is simple,and suitable for the simultaneous determination of the two constituents in compound minoxidil gel.