Reverse-phase liquid chromatographic determination of clioquinol in cream and ointment preparations: collaborative study.
Seven laboratories participated in a collaborative study to analyze, in duplicate, 2 synthetic formulations and 2 commercial preparations, labeled to contain 3% clioquinol. Clioquinol is determined as its nickel (II) complex by reverse-phase liquid chromatography on a phenyl-bonded column with a mobile phase of acetonitrile-methanol-water, containing ammonium acetate and nickel chloride. Detection is at 273 nm and diphenylamine is added as an internal standard. Mean recoveries were 99.1 and 101.1%, respectively, for the ointment and cream synthetic preparations and 96.7 and 99.7%, respectively, for the commercial ointment and cream. All results are consistent with the variability of other methods at this concentration range. The method has been approved interim official first action.
Wojtowicz
E J
EJ
Food and Drug Administration, Buffalo, NY 14202.
D002853:Chromatography, Liquid; D007464:Clioquinol / Q000032:analysis*; D006912:Hydroxyquinolines / Q000032:analysis*; D007202:Indicators and Reagents; D009824:Ointments
D006912:Hydroxyquinolines; D007202:Indicators and Reagents; D009824:Ointments; D007464:Clioquinol