Effect of pH on fractional precipitation for pre-purification of paclitaxel from plant cell cultures

Abstract

Fractional precipitation is a simple, efficient method for pre-purifying paclitaxel from plant cell cultures of Taxus chinensis. The pH, a key process variable in fractional precipitation, was optimized in terms of the yield and purity of paclitaxel with a fixed methanol concentration in water (61.5%, v/v), paclitaxel content in the crude extract (0.5%, w/v), and storage time (14 hr). The maximum yield (~99%) and purity (~84.4%) of paclitaxel were obtained at pH 8.0 with potassium phosphate buffer. The precipitate from fractional precipitation was an amorphous state paclitaxel by analysis of XRD and SEM. Also, the particle size distribution of dried precipitate was a range of approximately 119-411 µm. The use of fractional precipitation in the pre-purification process allowed for rapid and efficient separation of paclitaxel from interfering compounds, and dramatically increased the yield and purity of the crude paclitaxel for subsequent purification steps.

Preparation and characterization of biodegradable paclitaxel loaded alginate microparticles for pulmonary delivery

“…As seen in Fig. 6A, B and 6D similar to previous studies pure paclitaxel [81][82][83], blank alginate microparticles [84,85] and physical mixture of blank alginate microparticles and paclitaxel indicates an amorphous pattern in X-ray diffractograms because there is no meaningful peak in the XRD patterns. However, XRD pattern of paclitaxel loaded microparticles, in Fig.…”

“…X-ray diffraction X-ray diffraction (XRD) is a proven tool to study crystal lattice arrangements and yields very useful information on degree of sample crystallinity [15]. Due to the fact that paclitaxel exists in different modifications containing two anhydrous, amorphous, and dihydrate forms with different thermal properties, X-ray diffraction was used for further evaluation of the dispersion state of paclitaxel and to identify the morphologies of the prepared samples [80][81][82]. Fig.…”