earticle

영어

Fractional precipitation based on the difference in solubility of crude paclitaxel dissolved in methanol, to which distilled water must be added, is the most effective method for the pre-purification of paclitaxel. In this study, the effect of the distilled water feeding and mixing method on the efficiency (purity and yield) of fractional precipitation and the formation of paclitaxel precipitate were evaluated. The highest purity (~57.0%) and yield (~81.0%) of paclitaxel were obtained when distilled water was made pH 8.0 using ammonium phosphate buffer. When the distilled water was added all at once, the highest purity (~57.0%) and yield (~81.0%) were obtained, and a spherical precipitate was formed by the clustering of crystal branches. On the other hand, when the distilled water was added intermittently in several aliquots, the purity and yield of paclitaxel tended to decrease with increasing number of additions, and the precipitate took the form of a cross or pentagon with less clustering of branches, indicating impeded crystal growth. Not mixing after the addition of distilled water resulted in high purity (~57.0%) and the
formation of a spherical precipitate that showed increased branching around the nucleus over time. In contrast, when the sample was mixed intermittently after adding distilled water, paclitaxel was obtained in high yield (~99.7%). Continuously mixing the sample after adding distilled water, however, caused the precipitate crystals to be broken into smaller pieces. Based on these results, the optimal strategy for the pre-purification of paclitaxel by fractional precipitation will ultimately be established.