Simultaneous NP TLC Analysis of the Sunscreens Diethylamino Hydroxybenzoyl Hexyl Benzoate and Octyl Methoxycinnamate

A simple, rapid, and effective method for TLC separation of two EU-authorized UV filters octyl methoxycinnamate (OMC) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB) on silica gel 60 is proposed. Separation conditions were optimized and cyclohexane-diethyl ether-acetone 15:1:2 (v/v) was used as mobile phase. Quantification of both filters on the same chromatographic plates was achieved by densitometric scanning in absorption-reflectance mode at 300 and 360 nm, respectively. The method enabled separation of other UV-absorbing ingredients commonly found in cosmetic sunscreen preparations, for example parabens or ethylhexyltriazone (ET). Good quality, linear calibration plots were generated over the range 200–2000 ng per spot both for OMC and DHHB. The method was validated.