For selective extraction and on-line chromatographic purification of natural molecules
A Problematic Situation
Current manufacturing methods for natural pharmaceuticals use large volumes of toxic organic solvents to extract the active ingredients that occur in trace amounts (5 to 500 parts per million). Process yields are low, and procedures are time-consuming and resource-intensive. The toxic organic solvents used are not readily recyclable, require expensive disposal and often leave toxic residuals.
The Need For Change
For example, paclitaxel (Taxol®) was initially isolated from the bark of the slow growing Pacific yew, Taxus brevifolia, by several toxic organic solvents in as many as 19 processing steps. The bark of 100- to 200-year-old Pacific yews was used, even though it killed the tree, because it was a relatively clean matrix that made the isolation possible.
The manufacturing of paclitaxel from yew bark was thus based on a species that was becoming rapidly endangered and a technology that generated a significant amount of environmental waste.
However, the isolation and purification of paclitaxel from yew needles, the renewable portion of the tree, by conventional organic solvent procedures was made extremely difficult by the presence of non-polar waxes, lipids, chlorophylls and other bioactive compounds in the yew needle.
The CXP Solution
The SuperFluids™ (supercritical, critical or near-critical fluids with or without polar cosolvents) extraction and purification (CXP) process circumvents these manufacturing difficulties and resource limitations.
By utilizing SuperFluids™, CXP selectively extracts and purifies paclitaxel and related taxoids from yew needles (leaves), a renewable biomass resource, of the cloned ornamental yew, Taxus media "hicksii", in just five steps.
The CXP Process