HPLC determination of imidazole antimycotis in antidandruff cosmetic products

A simple HPLC method for the determination of imidazole antimycotics in cosmetic antidandruff formulations has been developed. HPLC was carried out on a Discovery RP-Amide C16 column and spectrophotometric detection was performed at 220 nm. The initial mobile phase was a mixture of acetonitrile and aqueous 10(-3) M NaClO4 (pH 3.0) in the ratio of 15:85 (v/v); then a linear gradient up to 46% acetonitrile in 70 min, and up to 50% in 80 min. The extraction procedure has been validated by analyzing samples of shampoo and lotion spiked with 1% of the active principles. The recoveries were greater than 95% and the reproducibility was within 3%.