Solubility phase diagramThe solubility of warfarin in different types and concentrations of Eudragit acetone solution was deter- mined, according to our previous study (Lin and Perng, 1993). The dissolved warfarin in acetone was filtered through a membrane filter, suitably diluted with acetone and assayed spectrophotometrically at 329 nm. Each study was carried out in triplicate, and a mean was obtained.