DETERMINATION OF VITAMIN-A, VITAMIN-E, AND THEIR ESTERS IN TABLET PREPARATIONS USING SUPERCRITICAL-FLUID EXTRACTION AND HPLC

A rapid and precise method for the isolation of vitamins A and E and t heir acetate or palmitate esters from tablet matrices was developed us ing supercritical fluid extraction (SFE). The vitamins were analyzed b y nonaqueous reversed-phase high-performance liquid chromatography aft er a 15-min extraction of the dosage form with supercritical carbon di oxide at 40 degrees C and at a pressure of 250 atm. A quantitative com parison of SFE with an established liquid extraction procedure was per formed on commercial tablet formulations. Vitamin recoveries of over 9 5.6% compared with conventional liquid extraction were achieved by the SFE technique with a much shorter sample preparation time (15 min vs 2 h). Moreover, the automated SFE process minimized the number of samp le handling operations, drastically reduced the consumption of harmful solvents, and provided mild extraction conditions for the analysis of the labile vitamins. The described SFE method is suitable for quality control analyses of pharmaceutical tablets.