Assay of vitamin A palmitate and vitamin E acetate in cosmetic creams and lotions by supercritical fluid extraction and HPLC.

The use of supercritical fluid extraction (SFE) as an alternative to liquid extraction was examined for the isolation of vitamin A palmitate and vitamin E acetate from cream and lotion preparations. Investigation of the factors controlling the extraction efficiency in SFE indicated that vitamin recoveries were affected mainly by the extraction pressure and by the degree of sample dispersion. The vitamins were analysed by high-performance liquid chromatography after a 30-min extraction of the cosmetic product with supercritical carbon dioxide at 40 degrees C and at a pressure of 250 atm. Compared with conventional liquid extraction SFE produced slightly lower recoveries (> 91.6%) but afforded a more effective purification of the cosmetic matrices. Moreover, SFE minimized sample handling and the use of harmful solvents and provided mild extraction conditions for the analysis of the labile vitamins. Vitamin E acetate and vitamin A palmitate were assayed in commercial cream and lotion formulations using the proposed SFE technique.