Organic solvent vapor effects on phase transition of α and β tegafur upon grinding with solvent additives

Solvent effects on alpha tegafur (5-fluoro-1-(tetrahydro-2-furyl)uracil) phase transition to beta tegafur during grinding with solvent additive, as well as phase transition in samples exposed to 95% relative solvent vapor pressure has been studied in this research. Samples containing 0.5% and 0.1% of beta tegafur in alpha and beta tegafur mixture, as well as samples of pure alpha tegafur were ground with different solvent additives, and conversion degrees depending on the solvent were determined using PXRD method. Samples with alpha and beta tegafur weight fraction of 1:1 were exposed to 95% relative solvent vapor pressure, and phase transition rates were determined. Solubility of alpha tegafur, solvent sorption and desorption behavior on alpha and beta tegafur have been examined . It was found that the conversion degree of alpha tegafur to beta tegafur mainly depends on solubility of beta tegafur in the relevant solvent, and the conversion degree to beta tegafur is higher in such solvents, where solubility of beta tegafur is higher. The samples ground in a ball mill with solvent additive had a trend of phase transition dynamics from alpha tegafur to beta tegafur similar to the samples exposed to 95% relative solvent vapor pressure. (C) 2013 Elsevier B.V. All rights reserved.