USE OF MICELLAR MEDIA FOR THE FLUOROMETRIC-DETERMINATION OF ELLIPTICINE IN AQUEOUS-SOLUTIONS

Ellipticine is a pyridocarbazole alkaloid with interesting antitumour activity. Use of neutral ellipticine is hampered by its very low water solubility and therefore this compound has been administered as a sal t; however, nitrogen quaternization modifies the antitumour properties of ellipticine. Potential alternatives to quaternization include the use of cyclodextrins, and also the use of micellar media. The latter p ossibility is explored in this work as an analytical tool. The results obtained with model anionic (SDS), cationic (CTAB) and neutral (Brij- 35) surfactants are described. Fluorimetric analysis shows that ellipt icine solubilizes completely in the presence of all these compounds, a s a result of its aromatic, planar structure. The use of micellar medi a considerably increases the slopes of the calibration curves with imp roved correlation coefficients (e.g. 0.8904 in water and 0.9982 with S DS). Micellar media also modify proton transfer processes, as a conseq uence of the apolar environment of the micellar phase. Deprotonation o f ellipticine is hampered in SDS because of the relationship between t his process and the surface charge of the micelles. Finally, fluoresce nce quenching in micellar media has been studied, it being found that surfactants provide protection towards this phenomenon.