HPLC method for detecting prostaglandin F2α analogs in cosmetics: Optimization for chromatographic separation and sample preparation

Abstract

Some prostaglandin F_2α (PGF_2α) analogs, including bimatoprost and tafluprost, are pharmaceutical substances known to cause specific abnormal reactions that promote eyelash growth. However, research on the simultaneous analysis of multiple PGF_2α analogs using HPLC–UV or DAD techniques is limited. In this study, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous analysis of 11 PGF_2α analogs, optimizing both the analytical column and sample preparation method. Five columns with varying particle sizes, lengths, and packing types were compared to select the optimal analytical column. The separation efficiency of the columns was confirmed by comparing their chromatographic parameters, including retention time, resolution, number of theoretical plates, and height equivalent to a theoretical plate. Solid-phase extraction (SPE) was used to pretreat cosmetic samples, and the washing solvent and cartridge type for the SPE process were optimized. The established HPLC method was validated in terms of linearity, limits of detection and quantification, recovery, accuracy, and precision. The verified analytical method was applied to eyelash serums currently available in the market, and norbimatoprost was detected in one product. The HPLC method proposed in this study may help prevent the distribution of cosmetics containing illegal PGF_2α analogs.